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: completing a circuit causes electricity to flow through that circuit, Fact2: Electricity is electrons in motion., Question: what flows through a circuit when it is completed? (A) energy (B) insulators (C) heat energy (D) electrons (E) protons (F) direct energy (G) light switch (H) Solar energy
Output:
D