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: thirst is used to make an animal realize that it needs to replenish its bodily water by the body, Fact2: An example is H2O which shows water is made of two atoms of hydrogen stuck to one atom of oxygen., Question: Thirst shows an animal that it needs what? (A) CO2 (B) H2O (C) He (D) food (E) feed (F) urea (G) O2 (H) H20
Output:
B