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.

Input: Consider Input: Article: Throughout history there have always been people who can make other people laugh. Early clowns often both annoyed and delighted listeners with their comments and songs. They were not the silent performers seen in today's circus rings. Clowns _ when the big three-ring circuses made it impossible for the audience to hear them. Circus clowns give performances in various ways. Walk-around clowns use an animal or something, like a huge rubber hammer, as part of their performance. A carpet clown moves around, talking with the audience and performing while the acts change in the rings. Then there are acrobatic clowns, riding clowns, juggling clowns and others. Everything a clown does looks easy, but it is not. Making people laugh can be hard work. Clowns must be in good physical condition to prevent injuries. Each funny move is carefully timed and well-rehearsed . Most clowns have also been trained as acrobats, jugglers or aerial artists, and many include such skills into their acts. Generally, there are three types of circus clowns--whiteface, auguste and character. Each has a special makeup and clothes. Each has a typical act as well. The neat whiteface is usually a strict, in-charge character who sets up the punch line (the point of a joke) with a partner who is typically an auguste. His facial makeup is neatly detailed in red or black, and his clothes look so loose with a ruffle around the neck. Old circus stories have it that the auguste clown got his name from a German nickname for someone who is clumsy, acting in a careless and stupid way. The auguste wears light-coloured makeup, but white is used around the mouth and eyes, and there's a big red nose. This clown performs a great deal of humour. An oversized suit or baggy trousers allow freedom of movement for all the clumsy acts. He also wears big shoes. Character clowns perform as different characters--cowboys, grandmothers or concert conductors. The most famous character clown, however, is the tramp . Tramps wear different styles of makeup and torn clothes. Some tramp clowns are happy-go-lucky. Others are extremely sad. Still others act like gentlemen who just happen to be out of money.
Question: By saying that clowns "lost their voices", the author means they _ .
Options: (A) became silent to avoid annoying people (B) began to perform silently because of larger audiences (C) realized audience members often spoke another language (D) discovered that three-ring circuses were becoming more popular

Output: B

Input: Consider Input: Article: On a Friday night, a poor young artist stood at the gate of the New York railway station, playing his violin. The music was so great that many people stopped to put some money into the hat of the young man. The next day, the young artist came to the same place, and put his hat on the ground gracefully. Different from the day before, he took out a large piece of paper and laid it under his hat. Then he began to play the violin. It sounded more pleasant than ever. Soon he was surrounded with people who were attracted by the words on that paper. It said, "Last night, a gentleman named George Sang put an important thing into my hat by mistake. Please come to claim it soon." After about half an hour, a middle-aged man rushed through the crowd to the violinist and said, "Yes, it's you. I knew that you were an honest man and would certainly come here." The young violinist asked calmly, "Are you Mr. George Sang?" The man nodded. The violinist asked, "Did you lose something?" "It's a lottery ticket," said the man. The violinist took out a lottery ticket on which George Sang's name was seen. "Is it?" he asked. George nodded and took the lottery ticket and kissed it, then danced with the violinist. The violinist was a student at an arts college and had planned to attend advanced studies in Vienna. Later his classmate asked the violinist, "At that time you needed money to pay the tuition and you had to play the violin in the railway station every day to make money. Why didn't you keep the lottery ticket for yourself?" The violinist said, "Although I don't have much money, I live happily. But if I lose honesty I won't be happy forever." Through our lives, we can gain a lot and lose so much. But being honest should always be with us.
Question: What did the young artist do at the railway station on Friday?
Options: (A) He played the violin to make some money. (B) He waited for the train to Vienna. zxxk (C) He came to buy a train ticket to Vienna. (D) He walked around the New York railway station.

Output: A

Input: Consider Input: Article: Rising levels of carbon dioxide in the atmosphere are a major cause of climate change, and now a new study has confirmed that atmospheric CO2is also affecting the ocean chemistry and potentially harming sea life. Montana State University scientist Robert Dore has been researching the water in the Pacific Ocean for almost two decades. We've been going to the same spot in the Pacific Ocean, and we try and characterize long-term change in the open ocean environment. And one of the key things that we measure is CO2levels. And we've been able to record this increasing quantity of atmospheric CO2into the ocean. Scientists expected that as atmospheric CO2increased, more and more of the carbon dioxide would be absorbed into the ocean, affecting the chemical balance of the sea water, with a potentially harmful impact on shellfish and coral in particular. "As carbon dioxide dissolves in the water, or seawater in this case, it forms a weak acid, carbonic acid," Dore explains. "And therefore, as the concentration of CO2in the atmosphere goes up and that exchanges with the surface seawater, it drives the PH down, and makes it more acidic." The seawater Dore and his colleagues have analyzed confirms what the theory predicts. The effect was particular striking at about 250 meters down, and again at 500 meters. Dore and his colleagues came up with two possible explanations. It could be that surface water picked up CO2and then moved to those depths. Or there could be a biological explanation. "It's important to realize that the oceans are really becoming acidic. And it can have negative impacts on a whole variety of sea life from fish to coral. It's potentially catastrophic."
Question: What can be the best title of the passage?
Options: (A) Sea Life Facing Danger (B) Scientist Researching Seawater (C) Oceans Becoming More Acidic (D) Climate Change Affecting Seawater
Output: A