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 input: 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
Example output: B
Example explanation: 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.
Q: Article: Carnival is an explosion of joy. It is a festival that mixes creativity, color1s, sounds, costumes and so on. The carnival in Rio starts on Saturday, and ends on Tuesday. Little need to be said about the carnival in Rio. Every year, Rio hosts the world's largest carnival. The samba school parades are world-famous. The festival begins officially when the city's mayor hands over a giant silver and gold key to the Fat King (King Momo) . Then people dance, sing, party and have tons of fun. There are many parties that take lace before, during and after the carnival all night and all day. Samba schools are not teaching institutions as their names suggests and do not offer samba classes.There are over 70 samba schools in Rio de Janeiro and they all parade during the 4-day celebration.They are organized into six competitive leagues.They are the Special Group A,B,C,Dand E.The first three groups parade in the Sambodromo.The other groups parade on the streets and are free to watch and join in.The biggest and most popular 12 leading schools are from the Special Group.They create a pageant with 3,000 to 5,000 people competing in the Samba Parade in the Sambodromo on Carnival Sunday and Monday. Balls takes place every night throughout the week, together with a variety of costume contests. One of the most frequent questions we hear is " What is the date of the carnival this year?" Well, believe it or not , it is not an easy question to answer. You have to be part astrologer , part mathematician, and part priest.
Question: The carnival in Rio will begin officially when _
Options: (A) the mayor announces officially (B) King Momo appears (C) King Momo takes over the key of the city. (D) the mayor comes with the King Momo.
A:
C