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: Planting certain crop plants in a field causes a disruption of the natural nitrogen cycle in that field. Which outcome would this disruption most DIRECTLY cause in the field over time?  
 (A) topsoil erodes (B) soil nutrients decrease (C) desert conditions appear (D) atmospheric carbon dioxide increases
Example Output: B

Example Input: The change in fur color of the Arctic hare from brown in the summer to white in the winter is an example of  
 (A) mimicry. (B) heredity. (C) diversity. (D) camouflage.
Example Output: D

Example Input: The abundance of a mineral at the surface of Earth most likely depends upon the  
 (A) climate of a particular region. (B) types of elements available in the crust. (C) thicknesses of nearby rock layers. (D) exposure of the elements to the environment.
Example Output:
B