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: Roni was playing with a beach ball at the beach. She noticed that when she rolled the ball on the sand, it traveled slower than when she rolled it on the wooden boardwalk. Question: Which surface provides more resistance? (A) sand (B) boardwalk
sand