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.

Example Input: Which is most likely a genetic adaptation of desert plants to survive the hot, dry climate conditions?  
 (A) thin bark (B) waxy leaves (C) leaves that remain all year (D) flowers that bloom all year
Example Output: B

Example 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.
Example Output: A

Example Input: A 20-N force acts on a 5-kg object at rest. How fast will the object accelerate on a frictionless surface?  
 (A) 4 m/s^2 (B) 15 m/s^2 (C) 25 m/s^2 (D) 100 m/s^2
Example Output:
A