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: the type of material through which sound passes changes the speed at which sound travels, Fact2: Sound vibrations travel at different speeds through different materials., Question: the type of material through which sound passes changes the what? (A) vibrating mass (B) occurs over a wide range (C) passage of time (D) relationship (E) rapid changes occur (F) 70-75 degrees Fahrenheit (G) sound vibrations (H) sound of silence
Output:
G