Instructions: 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: Fact1: Organisms cluster around hydrothermal vents in the ocean floor., Fact2: Animals at underwater hydrothermal vents are unique., Question: What are organisms on the ocean floor? (A) conventional (B) common (C) unique (D) protected (E) parasites (F) tortoises (G) normal (H) bacteria
Output:
C