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: Plants exhibit phototropism, or growing toward a light source., Fact2: Green plants use light as their primary energy source., Question: Phototropism means growing toward what? (A) rocks (B) energy (C) retina (D) light (E) heat (F) The Sun (G) plants (H) sand
Output:
D