Instructions: 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: water causes refraction of light, Fact2: Water includes all liquids., Question: What causes the refraction of light? (A) focusing a lens (B) Chemical energy (C) fossil fuels (D) all liquids (E) a solute (F) chemical changes (G) an electron lens (H) squids
Output:
D