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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.

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: B
Why? 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.

New input: Article: It was terribly cold and nearly dark on the last evening of the old year, and the snow was falling fast. In the cold and the darkness, a poor little girl, with bare head and naked feet, wandered through the streets. It is true she had on a pair of slippers when she left home, but they were not of much use. They were very large, so large, indeed, that they had belonged to her mother, and the poor girl had lost them in running across the street to avoid two carriages that were rolling along at a terrible rate. One of the slippers she could not find, and a boy seized upon the other and ran away with it. So the little girl went on with her little naked feet, which were quite red and blue with the cold. In an old apron she carried a number of matches, and had a bunch of them in her hands. No one had bought anything of her the whole day, nor had any one given her even a penny. Lights were shining from every window, and there was a delicious smell of roast goose, for it was New-year's eve--yes, she remembered that. In a corner, between two houses, one of which projected beyond the other, she sank down and huddled herself together. She had drawn her little feet under her, but she could not keep off the cold; and she dared not go home, for she had sold no matches, and could not take home even a penny of money. Her father would certainly beat her; besides, it was almost as cold at home as here.
Question: The story happened _ .
Options: (A) on New-year Day (B) on Christmas (C) on a rainy evening (D) on a snowy night
Solution:
D