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.
Q: Sentence: Tim has to push an ice sculpture across the ballroom in order to get his restaurant ready for a wedding. He notices that it is easier to push the sculpture when he moves it across the polished ballroom floor than when he moves it across the rough cobblestone floor. Question: If Tim is trying to keep the ice sculpture from melting, which surface should he push it across in order to produce less heat? (A) ballroom floor (B) cobblestone floor
A:
ballroom floor