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.

Example 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
Example output: Jacob
Example explanation: Typically, people with thin frail legs squat less weight than people with big strong legs, so the answer is Jacob.
Q: Sentence: A shopping cart rolls by itself across a parking lot. Then it gets to a field. The cart rolls only a little more after it enters the field. Question: Why does this happen? (A) the parking lot is a rougher surface (B) the field is a rougher surface
A:
the field is a rougher surface