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: The changing appearances of the nighttime sky over the surface of Earth and eclipses of the Moon have provided evidence that  
 (A) Earth is a sphere. (B) Earth supports life. (C) Earth has a layered atmosphere. (D) Earth is covered mostly with water.
Example Output: A

Example Input: Which two protein molecules are essential for muscle contraction and relaxation?  
 (A) actin and myosin (B) collagen and tubulin (C) hemoglobin and myoglobin (D) amylase and polymerase
Example Output: A

Example Input: A volcano under the ocean slowly releases lava over time. As the lava is released, it cools and hardens on the ocean floor. Which feature will most likely form from the release and cooling of the lava on the ocean floor over time?  
 (A) a fault (B) an island (C) a reef (D) a sandbar
Example Output:
B