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: Amylase is a chemical that decomposes starch into maltose and dextrin. Which best describes the role of amylase in the human body?
(A) as an inhibitor of insulin production (B) as an enzyme that aids in digestion (C) as a catalyst for protein synthesis (D) as a receptor of fatty acid chains
Example Output: B

Example Input: If an ecosystem's balance is disturbed by a volcanic eruption, what will most likely occur?
(A) The ecosystem will not change from its original state. (B) The ecosystem will eventually become balanced again. (C) The consumers in the ecosystem will begin to consume carbon dioxide. (D) The consumers in the ecosystem will begin to produce more oxygen.
Example Output: B

Example Input: The engine of an automobile is part of which type of system?
(A) structure (B) propulsion (C) guidance (D) control
Example Output:
B