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: temperature changing can cause phase changes, Fact2: Melting is the change of phase from a solid to a liquid., Question: What can cause melting? (A) Changing pressure (B) Heat energy (C) Water expanding (D) Evaporation (E) converting electricity to heat (F) Increase in mass (G) Temperature changing (H) Chemical reaction
Output:
G