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.

[EX Q]: Article: Many people cannot start their day without first having a cup of coffee or tea.These drinks help them think clearly and feel more awake.This is because of caffeine,which helps to give a jump start to the nervous system.Now,a report says it may also boost long-term memory. Mike Yassa is a neurobiology professor.He and other researchers wanted to know if caffeine could improve a person's memory.He explains,"After you learn anything,it takes some time for that memory to strengthen.And over the first 24 hours is actually where most of   the forgetting happens.So that is where we wanted to intervene with caffeine and see if we can help reduce this forgetting." They took 160 caffeine-free people and showed them pictures of everyday objects. These people were asked if the objects could be found inside the house, or outdoors.Then some of the subjects were given a caffeine pill.The others were given a placebo--a pill containing nothing. 24 hours later,the subjects were shown the exact same images from the day before.They were also shown images with slight differences,and some completely new images. Both groups correctly identified the exact same and completely new pictures.But those who took the caffeine pill were better at spottingthe pictures that were slightly different. Professor Yassa says their answers helped to show the effects of caffeine on memory. And  we find that if they are on caffeine they are much more likely to make the right decision." The amount of caffeine the researchers used in the study was similar to one cup of strong coffee.The researchers did not see any improvement to memory from smaller doses of caffeine or when it was given an hour before viewing the images. 
 Question: What is the focus of the text? 
 Options: (A) Caffeine can make people addicted. (B) Caffeine can make people energetic. (C) Caffeine can improve long--term memory. (D) Caffeine can make people feel comfortable.
[EX A]: C

[EX Q]: 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.
[EX A]: C

[EX Q]: Article: Whether you live in Seattle or the Sahara desert, the time has come to invest in a good raincoat or umbrella, a new study suggests. As global temperatures continue to rise, more "extreme rain" events--intense, cats-and-dogs downpours--can be expected, said thestudy, published Monday in the journalNature Climate Change. And that, scientists said, means an increased flood risk, particularly for the world's driest areas. The study challenges the idea that global warming is causingdry areas to become drierand wet areas wetter. "In both wet and dry regions, we see these great increases in heavy precipitation ," lead author Markus Donat, a climate scientist at the University of New South Wales, told Nature. Donat and his team collected data from 1951 to 2010 on extreme precipitation events from 11, 000 weather stations around the world, Nature reported. In that time, the number of days with "extreme precipitation" increased 1 percent to 2 percent per decade. "We found a strong relationship between global warming and an increase in rainfall, particularly in areas outside of the tropics," Donatsaid in a statement. "Importantly, this research suggests we will see these extreme rainfall events increases at regional levels in dry areas, not just as an average across the globe," Donat added. Peter Stott, a senior climate scientist at Met Office, told Climate Central that the study's findings are important, because more violent rainfall and flooding will "challenge our capability to adaptto a rapidly changing climate." As Nature reported, the research aligns witha 2015 study that found global warming has led to a sharp increase in record-breaking precipitation events. Donat told Nature that his study should come as a warning to world governments. 
 Question: Which of the following is one of the study's findings? 
 Options: (A) Global warming is causingdry areas to become drierand wet areas wetter. (B) Extreme rain events can be expected at regional levels in dry areas. (C) Extreme rainfall events increase at regional levels in wet areas. (D) Rainfall increases particularly in the tropics areas.
[EX A]:
B

