Teacher: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.
Teacher: Now, understand the problem? Solve this instance: Sentence: Tim threw a pebble down the mountain effortlessly, and it was out of site in seconds.  Bob rolled a boulder down the mountain, and after a minute of heaving, it finally descended, gaining speed as it went. Question: Which was heavier? (A) the boulder was heavier (B) the pebble was heavier
Student:
the boulder was heavier