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: In an electric motor, electrical energy is converted into  
 (A) mechanical energy. (B) chemical energy. (C) thermal energy. (D) light energy.
Example Output: A

Example Input: Some kinds of fish live most of their lives in salt water but lay their eggs in freshwater. Their ability to survive in different environments is an example of  
 (A) adaptation (B) developmental stages (C) a habit (D) selective breeding
Example Output: A

Example Input: Which order of succession of natural communities would most likely occur in New York State?  
 (A) grasses -> trees -> bushes (B) trees -> bushes -> grasses (C) bushes -> grasses -> trees (D) grasses -> bushes -> trees
Example Output:
D