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: Migrants typically travel long distances., Fact2: Migrant birds arrive., Question: What travels long distances? (A) humans (B) jets (C) rocks (D) birds (E) camels (F) cocoons (G) Light (H) eggs
Example Output: D

Example Input: Fact1: Male dogs use pheromones in urine to mark their territory., Fact2: Pheromones are natural aphrodisiacs., Question: What do male dogs use in urine to mark their territory? (A) Natural aphrodisiacs (B) competing for resources (C) Tails (D) Urine cleaner (E) Something coming from a gland (F) Chemical energy (G) an area swollen with pus (H) Chew toys
Example Output: A

Example Input: Fact1: a laser is used for producing light, Fact2: Light reveals what lies hidden in darkness., Question: What can be used to reveal what lies hidden in darkness? (A) A laser (B) Night (C) photons (D) energy (E) Electrical (F) Blackness (G) heat (H) Hidden health issues
Example Output:
A