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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: Anyone driving the twists of Highway 1 between San Francisco and Los Angeles recently may have glimpsed a Toyota Prius car with a curious-looking thing on the roof. Harder to notice was that the person at the wheel was not actually driving. The car is a project of Google, which has been working in secret but in plain view( anyhow, no one can keep such a thing from the public) on vehicles that can drive themselves, using artificial-intelligence software that can sense anything near the car and imitate the decisions made by a human driver. With someone behind the wheel to take control if something goes wrong and a technician in the passenger seat to monitor the navigation system , seven test cars have driven 1,000 miles without human intervention and more than 140,000 miles with only occasional human control. One even drove itself down Lombard Street in San Francisco, one of the steepest and curviest streets in the nation. The only accident, engineers said, was that one Google car was rear-ended when it stopped at a traffic light. Autonomous cars are years from mass production, but technologists who have long dreamed of them believe that they can transform society as profoundly as the Internet has. Robot drivers react faster than humans, have 360-degree perception and do not get distracted or sleepy, the engineers argue. They speak in terms of lives that could be saved and injuries that could be avoided--- more than 37,000 people died in car accidents in the United States in 2008. The engineers say the technology could double the capacity of roads by allowing cars to drive more safely while closer together. Because the robot cars would eventually be less likely to crash, they could be built lighter, reducing fuel consumption. But of course, to be truly safer, the cars must be far more reliable than, say, today's personal computers, which crash on occasion and are frequently infected. The Google research program using artificial intelligence to revolutionize the automobile is proof that the company's ambitions reach beyond the search engine business. The program is also a departure from the mainstream of innovation in Silicon Valley, which has turned toward social networks and Hollywood-style digital media. However, the Google researchers said the company did not yet have a clear plan to create a business from the experiments.
Question: What can we learn from the passage?
Options: (A) Only seven autonomous cars have been created so far. (B) Nobody in the car took control during the 140,000miles trip. (C) It will take a long time before the autonomous car is put into the market. (D) When driving on the Lombard Street, all test cars broke down.
Solution:
C