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: Sales of crime novel The Cuckoo's Calling have rocketed since its author Robert Galbraith was unmasked as JK Rowling, according to The Bookseller. It said 17,662 hardback copies were sold between 14 and 20 July, up from just 43 copies the previous week, according to Nielsen BookScan data. The Cuckoo's Calling was the week's bestselling hardback novel, despite some booksellers running out of stock. The Harry Potter author was identified in a newspaper article last week. On a website Rowling said 8,500 English language copies had been sold in all forms, including e-books, before her unmasking. The author added that she had received two offers from television production companies. "The situation was becoming increasingly complicated, largely because Robert was doing rather better than we had expected him to," she said. "But we all still hoped to keep the secret a little longer.  Robert's success during his first three months as a published writer (discounting sales made after I was found out) actually compares favourably with JK Rowling's success over the similar period of her career." However, the Bookseller reported the hardback had sold fewer than 500 copies in its three-month period on sale before the Sunday Times' expose. The recent sales were not enough to send The Cuckoo's Calling to the top spot in the official UK top 50, instead landing it in third place. The Rowling revelation coincided with the paperback release of The Casual Vacancy -- her first official post-Potter work--which sold 19,548 copies in the same week, making the book number two in the sales chart. Neither title managed to draw John Grisham's The Racketeer from the top of the chart, which shifted 24,222 copies -- a 19% drop on the previous week. Elsewhere on the Robert Galbraith website, Rowling has revealed the reason she chose her pen name. She said she picked Robert because US senator Robert F Kennedy was her "hero" and she had never used the name in one of her earlier books.  "I can only hope all the real Robert Galbraiths out there will be as forgiving as the real Harry Potters have been," she wrote. A follow-up to The Cuckoo's Calling has been finished and should be published next year, the author added. 
 Question: What can we know about the sale of The Cuckoo's Calling? 
 Options: (A) The English edition sells better than other editions. (B) The sales have come across decline in recent weeks. (C) The sale is beyond satisfaction before J.K. Rowling unmasked. (D) Book sellers can't cover any expense for the running out of the stock.
Solution:
C