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").

Ex Input:
Fact1: Mutualism is a symbiotic relationship in which both species benefit., Fact2: Dogs and humans are symbiotic species., Question: what exists between dogs and humans? (A) mutualism (B) gravity (C) communication (D) antigens (E) several genes (F) space between (G) electrons (H) german shepherd

Ex Output:
A

Ex Input:
Fact1: soil is formed by rocks eroding, Fact2: Rivers erode the rocks they flow over., Question: What is formed by rivers? (A) fish (B) soil (C) rain (D) bamboo (E) spring (F) clouds (G) kayaks (H) NaCl

Ex Output:
B

Ex Input:
Fact1: Thyroid hormones increase the rate of metabolism in cells throughout the body., Fact2: TSH, which is secreted by the pituitary gland, stimulates the thyroid gland to produce hormones., Question: Which gland has the largest impact on human metabolism? (A) three (B) Pituitary (C) Energy (D) Chlorophyll (E) Sweat (F) energy usage (G) Salivary (H) Mammary

Ex Output:
B