Definition: You are given a sentence, a question and two answer options ('A' and 'B'). Your task is to find the correct answer (return the string of the correct option, not 'A' or 'B') for the given question.

Positive Example 1 -
Input: Sentence: Jacob and Benny are squatting at the gym. Jacob has thin frail legs and Benny has big strong legs. Question: Who squats less weight? (A) Jacob (B) Benny
Output: Jacob

Positive Example 2 -
Input: Sentence: The fastest land animal on earth, a cheetah was having a 100m race against a rabbit. Question: Which one won the race? (A) the cheetah (B) the rabbit
Output: the cheetah

Negative Example 1 -
Input: Sentence: Suppose your neighbor John is playing music and your friend Nikos at the end of the street is also playing music. Question: Who's music will appear to be louder? (A) John (B) Nikos
Output: Nikos

Negative Example 2 -
Input: Sentence: The Sun is closer to the Earth then the nearest star. Question: Which object looks bigger to someone standing on the Earth looking up? (A) Sun (B) Star
Output: Star

Now complete the following example -
Input: Sentence: A dirty tooth isn't as smooth as a clean tooth. Question: Which surface will a toothbrush move over at a greater rate of speed? (A) dirty tooth (B) clean tooth
Output: 


Output: clean tooth