user: Given the task definition, example input & output, solve the new input case.
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.
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
Output: B
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 case for you: Article: A whale that became stranded in the River Thames in Central London has died after attempts to save its life failed. The whole nation had been hoping for a more successful outcome to the attempted rescue, updates of which were shown on TV news programmes throughout the day and night.  The five- meter long bottle-nosed whale, which probably weighted about four tones, was first spotted in the river on Friday. There had been reports that a pod of whales had swum into the Thames Estuary earlier in the week, which caused terror among naturalists, as this kind of whale only thrives in much deeper water. It was the first sighting of the endangered species in the Thames since records began nearly a century ago. There was no more news of the pod, which suggests that most of them turned back and swam out to sea. However, one whale clearly became separated from this group. Incredibly, the first person to raise the alarm was a man who saw the giant mammal from the train he was on when it crossed the river. Almost immediately, a rescue attempt was mounted and further attempts to move the whale began on Saturday morning. After unsuccessfully attempting to gently encourage it to swim downstream of its own accord towards the Thames Estuary and eventually the sea, rescuers decided to move it onto the barge . The rescue operation involved winching the whale onto an inflatable raft which had been placed on the barge. 3,000 onlookers watched as the whale was treated with extreme care by the rescuers and applauded when the transfer operation was complete. The barge then set off with the intention of freeing the whale in deeper water. Sadly, it began to convulse during the journey and died. Earlier in the day,  naturalist and TV presenter Terry Nuktins had warned that attempts to move the large mammal were misguided and that the proximity of the rescuers to the whale was potentially disastrous. He said that the whale would have been terrified by the people around it and it wouldn't have been used to the sight of boats and the noise of the engines and propellers. 
 Question: People throughout the country learned about the attempted rescues by_. 
 Options: (A) listening to the radio (B) reading newspapers (C) watching TV news (D) asking some rescuers
Output:

assistant: C