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: Just five minutes of exercise a day outdoors can improve mental health, according to a study. Researchers from the University of Essex, UK have found that as little as five minutes of a "green activity" such as walking, gardening, cycling or farming could help to improve mood and increase self-esteem . Many studies have shown that outdoor exercise can reduce the risk of mental illness and improve a sense of well-being, but the new study, led by Jules Pretty and Jo Barton, was the first to determine how much time needed to be spent on green exercise for the benefits to show. Barton and Pretty looked at data from 1,252 people of different ages, genders and mental health status taken from 10 studies in Britain. They analyzed their different outdoor activities including walking, gardening, cycling, fishing, boating, horse-riding and farming in locations such as a park, garden or nature trail . They found that the mental health changes were seen after just five minutes. With longer periods of time exercising in a green environment, the positive effects were more apparent. Looking at men and women of different ages, the researchers found the health changes were particularly strong in the young and the mentally ill. Green and blue A bigger effect was seen with exercise in an area that also contained water - such as a lake or river. "This is because historically we are drawn to water to survive and it is in our genetic make-up to be at one with nature," the researchers wrote in their report. Pretty said those who were generally inactive, or stressed, or with mental illness would probably benefit the most from "green exercise". "Employers, for example, could encourage staff in stressful workplaces to take a short walk at lunchtime in the nearest park to improve mental health." He also said exercise programs outdoors could benefit youth offenders.
Question: How is the study this article refers to different from other studies?
Options: (A) It determined the exact amount of time needed. (B) It took longer to finish the research. (C) It involved more people. (D) It was led by just two researchers.
Answer:
A