You will be given a definition of a task first, then some input of the task.
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").

Fact1: a generator converts kinetic energy into electrical energy, Fact2: Electricity is a powerful energy source., Question: Generators convert what into a powerful energy source? (A) circulatory systems (B) kinetic energy (C) engines (D) Organic compounds (E) organic molecules (F) rays or beams (G) a hydraulic system (H) photons
Output:
B