In this task, you're given an article, a question which often contains a blank and four options (associated with "A", "B", "C", "D"). Your task is to find the correct answer (from the given options) for the question from the given article and return one of the options from "A", "B", "C", and "D". Do not generate anything else apart from one of the following characters: "A", "B", "C", "D". There is only one correct answer for each question.

Example Input: Article: Life in the Clear Transparent animals let light pass through their bodies the same way light passes through a window. These animals typically live between the surface of the ocean and a depth of about 3,300 feet--as far as most light can reach. Most of them are extremely delicate and can be damaged by a simple touch. Sonke Johnsen, a scientist in biology, says, "These animals live through their life alone. They never touch anything unless they're eating it, or unless something is eating them." And they are as clear as glass. How does an animal become see-through? It's trickier than you might think. The objects around you are visible because they interact with light. Light typically travels in a straight line. But some materials slow and scatter  light, bouncing it away from its original path. Others absorb light, stopping it _ in its tracks. Both scattering and absorption make an object look different from other objects around it, so you can see it easily. But a transparent object doesn't absorb or scatter light, at least not very much, Light can pass through it without bending or stopping. That means a transparent object doesn't look very different from the surrounding air or water. You don't see it ----you see the things behind it. To become transparent, an animal needs to keep its body from absorbing or scattering light. Living materials can stop light because they contain pigments  that absorb specific colors of light. But a transparent animal doesn't have pigments, so its tissues won't absorb light. According to Johnsen, avoiding absorption is actually easy. The real challenge is preventing light from scattering. Animals are built of many different materials----skin, fat, and more----and light moves through each at a different speed. Every time light moves into a material with a new speed, it bends and scatters. Transparent animals use different tricks to fight scattering. Some animals are simply very small or extremely flat. Without much tissue to scatter light, it is easier to be see--through. Others build a large, clear mass of non-living jelly-lie material and spread themselves over it . Larger transparent animals have the biggest challenge, because they have to make all the different tissues in their bodies slow down light exactly as much as water does. They need to look uniform. But how they're doing it is still unknown. One thing is clear for these larger animals, staying transparent is an active process. When they die, they turn a non-transparent milky white. 
 Question: One way for an animal to become transparent is to   _  . 
 Options: (A) change the direction of light travel (B) gather materials to scatter light. (C) avoid the absorption of light (D) grow bigger to stop light.
Example Output: C

Example Input: Article: Experts believe that storms and severe weather in North America and Asia have disrupted bird flight paths across the world and swept huge numbers of bird species towards the British Isles. Birds flying to the other side of the Atlantic or to the Pacific to lay their eggs have been trapped in Britain and Ireland, adding their numbers to native species, and causing great excitement in the bird-watching community. Local birdwatchers have already observed a total of 442 species in the British Isles this year. The highest number ever seen in one year is 445, in 2008. "We only need four more to break our record," said Lee Evans, who runs the British Birding Association. "With three months to go I'm sure we'll do it." Last month an extremely rare Siberian Rubythroat bird was seen in Scotland, sending hundreds of birdwatchers north in the hope of catching a glimpse of this colourful Asian beauty. Another very uncommon bird, the bufflehead duck was cited in Cornwell and caused similar excitement. "I couldn't believe it," said Evans. "The poor thing was completely  _ . It must have been blown to England by the storms while trying to fly from Canada to the southern United States for the winter. That's 3000 miles!" Evans said that global warming over the past decade was playing a key role in transforming bird movements across the world. In addition, melting Arctic sea ice may also be opening up bird flight paths over the North Pole, making it easier for birds from the Pacific -- such as the slaty-backed gull and tufted puffin, both of which appeared in London earlier this year -- to reach Britain. Bird-watching is becoming an increasingly popular hobby among all age groups, added Evans. "A fifth of our members are under 18. This is a round-the-year hobby that you can enjoy from the kitchen window or from a car. More and more people are bird-watching, and as a result more and more unexpected species are being spotted in the British Isles." 
 Question: What is the passage mainly about? 
 Options: (A) The results of global warming. (B) Changes in the British bird population. (C) Increasing environmental pollution. (D) Worsening British weather.
Example Output: B

Example Input: Article: I was now in my twenty third year of residence in this island and was accustomed to the place and to the manner of living. If it had not been the savages who had come to the place to disturb me, I could have been content to spent the rest of my time there, even to the last moment, till I had laid me down and died, like the old goat in the cave. I had also arrived to some little recreations and amusements, which made the time pass more pleasantly with me a great deal than it did before. At first, I had taught my Poll to speak. And he did it so familiarly and talked so clearly and plain that it was very pleasant to me. And he lived with me no less than twenty six years. How long he might live afterwards, I don't know; though I know they have an idea in Brazil that they live a hundred years. Perhaps poor Poll may be alive there still, calling Poor Robin Crusoe to this day. I wish no other English man had the bad luck to go there and hear him. But if he did, he would certainly believe it was the devil . My dog was a very pleasant and loving companion to me, for no less than sixteen years of my time, and then died of mere old age. As for my cats, they multiplied to that degree that I had to shoot several of them at first to keep them from eating up all I had. Besides these, I had two more parrots which talked pretty well and would all call Robin Crusoe, but none like my first. Nor indeed did I take the pains with any of them that I had done with him. I had also several sea-fowls, whose names I don't know, that I caught upon the shore and cut their wings. And the little stakes which I had planted before my castle wall being now grown up to a good thick bush, these fowls all lived among these low trees and bred there, which was very agreeable to me; so that as I said above, I began to be well content with the life I led if not worried about the threat from the savages. 
 Question: What does the passage mainly talk about? 
 Options: (A) Robin Crusoe treated animals kindly. (B) Robin Crusoe led a hard life on the island. (C) The animals raised by Robin Crusoe brought him much pleasure. (D) The savages always spoiled Robin Crusoe's happy life.
Example Output:
C

