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: Elizabeth rolled an egg down a marble countertop in the kitchen. She then moved the egg to the knitted rug in the living room. She noticed that the egg moved faster on the countertop than on the rug. Question: On which surface was more heat generated? (A) countertop (B) rug
rug