Definition: 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").
Input: Fact1: coal is used to produce electricity by burning in coal-fire power stations, Fact2: Coal-fired power stations are inherently modular., Question: coal is used to produce electricity by burning in inherently modular what? (A) heat (B) stations (C) trees (D) heat energy (E) similar (F) cells (G) adding heat (H) engines
Output:
B