You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Input: Consider Input: Wave energy from the ocean can be harnessed to power generators to make electricity. Energy from ocean tides can also be used to make electricity. How would you categorize these two sources of energy?
(A) Both are renewable. (B) Both are nonrenewable. (C) Wave energy is nonrenewable. Tidal energy is renewable. (D) Wave energy is renewable. Tidal energy is nonrenewable.

Output: A

Input: Consider Input: Air is composed of many different substances. Which of the following components of air is a compound rather than an element?
(A) Argon, Ar (B) Oxygen, O2 (C) Water, H2O (D) Nitrogen, N2

Output: C

Input: Consider Input: What happens to water when it boils?
(A) It changes color. (B) It becomes heavier. (C) It changes into water vapor. (D) It stops bubbling.
Output: C