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 object is best used to demonstrate the bending of light as it passes through a substance?  
 (A) convex lens (B) flat mirror (C) opaque rod (D) concave mirror
Example Output: A

Example Input: Which would be the best method to use to dispose of cardboard boxes not utilized by a local grocery store?  
 (A) burn them once a month (B) send them to be dumped in a remote area (C) have them recycled for future paper products (D) put them into a dumpster with the rest of the trash
Example Output: C

Example Input: The populations of black rhinoceroses have been impacted by human interactions to the point of being endangered. Which interaction best explains why the black rhino is now endangered?  
 (A) over hunting (B) water pollution (C) airborne diseases (D) increased deforestation
Example Output:
A