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.

Let me give you an 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
The answer to this example can be: B
Here is 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.

OK. solve this:
Article: The Chinese put up with a lot living in the world's most populous country: standing on over-crowded trains for 40 hours; sleeping outside hospitals to secure a doctor's appointment; waiting more than a year to earn a driver's license. Add getting a U.S. entry visa to the list. Applicants here have waited as long as 60 days to secure an appointment at one of five U.S. consular locations in China that process visas. There, they're often greeted by long lines, followed by a face-to-face interview that can end badly in a matter of seconds. Now there are only about 100 U.S. visa officers in China, facing considerable challenges during the summer when tourists and students travel the most. "It's not easy work," Charles Bennett, minister-counselor for Consular Affairs at the U.S. Embassy in Beijing, said to his staff. "You're making, in some cases, life-changing decisions many times a day, and that can cause great tiredness." To adapt, US consular services expanded their hours, took on about a dozen additional staff and hope to have another 20 officers by spring. More facilities are also being expanded. Despite the shocking numbers, the embassy remains troubled by charges that it rejects applicants unreasonably and that the process is unfairly burdensome. "I'm fed up," said Wendy Liu, 24. The single woman from Beijing said she was recently refused a visa and told to re-apply when her personal life and finances were more stable. "I'll go anywhere but the U.S. now," she said. "I thought America was supposed to be a country of freedom." To visit the US, Chinese nationals must prove that they have enough money and family or business ties that make it likely they'll return to China. The Department of Homeland Security said it did not keep records on how many Chinese overstay their visas. Student visas can be refused on grounds of national security. Beijing native Tan Ge, 25, believes he was not accepted after he stated his interests in infrared technology and nanoelectronics on his application. He now studies in Canada after being forced to abandon a full scholarship to Arizona State University. By its very nature, the on-the-spot process at the U.S. Embassy can feel unbearable to Chinese applicants, who are asked to take their bank statements, property deeds , marriage licenses and HUKOU, a Chinese household ID. "It made me feel very uncomfortable," said Xu Yong, 28, a journalist who needed a business visa last month to cover a conference in New York. "They made me feel like someone from a Third World country up to no good." After giving his fingerprints, Xu waited to be called for his interview, sitting in an area that was as quiet as a library. Each passing minute seemed to be as long as a century. After an hour, Xu was called with three other people to a window for their interview. Two were rejected before his turn. Then the American officer, speaking fluent Chinese, reached for Xu's paperwork, asked some simple questions and said, "Congratulations." "I was so nervous. The first thing I did when I got out was to call my mom and tell her I passed," Xu said. "She was the one who warned me it wasn't going to be easy."
Question: Beijing native Tan Ge was refused a U.S. visa probably because he _ .
Options: (A) had no stable income (B) was supposed to be unsafe for the U.S. (C) had too wide interests (D) had got a full scholarship in the U.S.
Answer:
B