Q: 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.
Sentence: Karen was playing football at the park. She threw the ball and it hit the ground, rolled on the field, and then rolled into a gravel playground. The ball generated more heat when it rolled over the gravel. Question: Which surface is more level? (A) field (B) gravel
A:
field