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: Joann repeatedly overfed the fish in the pond behind her house. The nitrates from the excess food contributed to an overgrowth of algae. To correct the problem, Joann added more plants to the pond. How will adding more plants help?  
 (A) The plants make the pond look beautiful. (B) The plants will camouflage the green algae. (C) The plants will compete with algae for nutrients. (D) The plants will provide all the food for the fish.
Example Output: C

Example Input: A boy pulls a sweater off over his head. His hair is attracted to the sweater due to  
 (A) a magnetic force (B) a heat transfer (C) a chemical change (D) an electrical charge
Example Output: D

Example Input: The fur color of a bear varies with its environment. Polar bears found in the Arctic have white fur, while black bears found in Pennsylvania have dark fur. Which best describes the variation of fur color amongst the bear species?  
 (A) modified characteristic (B) ecological succession (C) structural adaptation (D) selective breeding
Example Output:
C