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: Which of these is a structure that is present in all organisms?
(A) a tissue (B) a cell (C) a stomach (D) a brain

Output: B

Input: Consider Input: In which case does a physical change occur?
(A) Ice melts into water. (B) Bread burns in a toaster. (C) A cake bakes in an oven. (D) Two chemicals form a new substance.
Output: A