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").

Example Input: Fact1: microorganisms can cause infections, Fact2: Bacteria are microorganisms that exist everywhere., Question: What can cause infection? (A) bacteria (B) seeds (C) influenza (D) disease (E) horses (F) viruses (G) chickenpox (H) bladders
Example Output: A

Example Input: Fact1: Echinoderms use pheromones to communicate with each other., Fact2: All echinoderms are deuterostomes ., Question: What use pheromones to communicate with each other? (A) passenger pigeons (B) honeybees (C) deuterostomes (D) Most plants (E) insects (F) animals (G) huddle together (H) orchids
Example Output: C

Example Input: Fact1: Electron transport is the final stage of aerobic respiration., Fact2: Aerobic respiration requires Oxygen., Question: What involves oxygen? (A) an engine (B) Burning fuel and air (C) space (D) carbon (E) Movement of an air mass (F) nitrogen (G) electron transport (H) igniting fuel and oxidiser
Example Output:
G