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.
One example: Article: Homework can put you in a bad mood , and that might actually be a good thing. Researchers from the University of Plymouth in England doubted whether mood might affect the way kids learn. To find out the answer, they did two experiments with children. The first experiment tested 30 kids. Someshapes were hidden inside a different, larger picture. The kids had to find the small shapes while sitting in a room with either cheerful or sad music playing in the background. To test their mood, the scientists asked the kids to point to one of five faces, from happy to sad. Children who listened to cheerful music tended to point to the smiley faces while the others pointed to the unhappy ones. The researchers found that sad kids took at least a second less to find the small shapes. They also found an average of three or four more shapes. In the second experiment, 61 children watched one of two scenes from a film. One scene was happy, and the other was sad. Just like in the first experiment, kids who saw the sad scene acted better compared to the others. The researchers guessed that feeling down makes people more likely to focus on a problem or difficult situation. Not all scientists agree with them, however. Other studies argued that maybe, that cheerful music in the first experiment distracted kids from finding shapes. While scientists work on finding out the answers, it still might be wise to choose when to do your tasks according to your mood. After eating a delicious ice cream, for example, write an essay. 
 Question: Researchers did experiments on kids in order to find out _ . 
 Options: (A) how they really feel when they are learning (B) whether mood affects their learning ability (C) what methods are easy for kids to learn (D) the relationship between sadness and happiness
Solution is here: B
Explanation: It is clearly mentioned in the article that to the check effect of mood on children is the main purpose of the experiment. So, B is the correct answer.

Now, solve this: Article: The supermarket of the past is racing toward a high tech future. And clever marketers are starting with their youngest customers. Publix Supermarkets in the prefix = st1 /U.S.city of Atlanta,Georgiahave begun testing TV Karts for little kids. Moms can shop in peace while their kids ride along watching their favorite TV shows. Marketers say the TV Karts bring about income by keeping children entertained so parents can shop longer. If the TV screen is not enough to hold a child's attention, parents can drop them off at a play center at Wegman' s supermarket in Virginia. There is adult care so parents can scan the grocery aisles without having to rush. And there are high tech toys for grown - ups, too. This computerized tablet is called the "Shopping Buddy". The small computer keeps a running tab of every item in the shopping cart. Customers can e - mail their grocery list and the device will let them know if any of the items are on sale. It also shows the location of the products. Stop and shop marketing manager Mike Grimes says the device can even take a deli order from customers on the other side of the store and let them know when it's ready for pick up. "The shopping buddy has two primary benefits to shoppers. The first - saving money, extra savings. The other thing it saves is time." If you really want to save time, "Veggie Vision", a computerized scale and camera, identifies various fruits and vegetables and automatically prices them for you. And when it's time to pay, a finger may be all you need. It takes just a few seconds for a machine to identify your unique fingerprint and debit your account. Two thousand stores in the U.S. now have the "Pay by Touch" biometric technology. Customers sign up by providing a bank account number and a fingerprint. Some European stores are testing tiny radio transmitters on their goods. The wireless devices can tell if a product is nearing its expiration date or needs to be restocked. And someday, as an I. B. M. commercial shows us, those transmitters will mean you may not even need your fingerprint to make a purchase. 
 Question: The main purpose of the passage is to introduce_. 
 Options: (A) some high supermarket technologies (B) the future supermarket (C) a special way of payment (D) the past supermarket
Solution:
A