You will be given a definition of a task first, then some input of the task.
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").

Fact1: Cells are the basic units of the structure and function of living things., Fact2: Proteins are needed for cell building., Question: What do living things need? (A) sunlight (B) body water (C) religion (D) water (E) oxygen (F) protein (G) ghosts (H) fun
Output:
F