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: Sal is looking at a map of Massachusetts. He has measured the distance, in inches, from Boston to Salem on the map. He wants to know how many actual miles the inches represent. What feature of the map should he look for?  
 (A) key (B) scale (C) legend (D) compass
Example Output: B

Example Input: Cell membranes allow some molecules to move freely across the membrane, while other molecules are restricted. Which term best describes this capability of a cell membrane?  
 (A) semipermeable (B) impervious (C) resilient (D) unyielding
Example Output: A

Example Input: Which diagram correctly shows the flow of energy in a food chain?  
 (A) Decomposer -> Consumer -> Producer (B) Producer -> Consumer -> Decomposer (C) Consumer -> Producer -> Decomposer (D) Producer -> Decomposer -> Consumer
Example Output:
B