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: Ejaculation occurs when muscle contractions propel sperm from the epididymes., Fact2: Male gametes are called sperm., Question: What is it called when male gametes are propelled because of muscle contractions? (A) competition (B) rapid expansion (C) intercourse (D) thrusting (E) a wave (F) reproductions (G) A Greek letter (H) ejaculation
Example Output: H

Example Input: Fact1: Biodiversity increases the productivity and stability of ecosystems., Fact2: Ecotourism, on the other hand, can help to conserve biodiversity., Question: What increases the stability of ecosystems? (A) overpopulation (B) water consumption (C) loose soil (D) Quality of life (E) agriculture (F) deforestation (G) ecotourism (H) trees
Example Output: G

Example Input: Fact1: a cavern is formed by carbonic acid in groundwater seeping through rock and dissolving limestone, Fact2: Limestone Limestone Limestone is a grey rock that is made of calcite., Question: What is formed when calcite is dissolved? (A) graptolites (B) patch reefs (C) a cavern (D) a solute (E) body water (F) tube (G) In sediment (H) glass
Example Output:
C