Detailed Instructions: In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").
Q: Fact1: a balance is used for measuring mass of an object, Fact2: Mass The base unit of mass is the gram., Question: What instrument measures in grams? (A) sweating (B) A balance (C) heat energy (D) A ruler (E) nutrients (F) An anemometer (G) energy (H) A thermometer
A:
B