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.

Ex Input:
Which type of organism is the best at fixing nitrogen?  
 (A) bacteria (B) fungi (C) protists (D) animals

Ex Output:
A


Ex Input:
Genes are located on chromosomes which are composed of  
 (A) DNA. (B) RNA. (C) ATP. (D) ADP.

Ex Output:
A


Ex Input:
Which instrument would be used when studying a unit on amphibian anatomy?  
 (A) a beaker (B) a telescope (C) a dissecting kit (D) a graduated cylinder

Ex Output:

C