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.

Ex Input:
When animals use energy, they produce  
 (A) nitrogen (B) iron sulfide (C) oxygen (D) carbon dioxide

Ex Output:
D


Ex 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

Ex Output:
B


Ex Input:
Which of the following events involves a consumer and producer in a food chain?  
 (A) A cat eats a mouse. (B) A deer eats a leaf. (C) A hawk eats a mouse. (D) A snake eats a rat.

Ex Output:

B