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: Consider Input: Fact1: water causes refraction of light, Fact2: Halos are produced by the refraction of light., Question: What causes halos? (A) germs (B) Pacific (C) solutes (D) water (E) storms (F) glass (G) algae (H) the sun

Output: D


Input: Consider Input: Fact1: wind and rain cause erosion, Fact2: Water, in the form of rain, is the most effective agent of erosion., Question: What causes erosion the most? (A) streams (B) motion (C) LEDs (D) water (E) Roads (F) rivers (G) Winter (H) wind

Output: D


Input: Consider Input: Fact1: Cartilage is a tough tissue that contains a protein called collagen., Fact2: Acid helps dissolve collagen., Question: what can acid help dissolve? (A) drink (B) layers of fat (C) an object (D) a solute (E) cartilage (F) Sediment (G) Bodily water (H) roots


Output: E