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

Ex Output:
A


Ex Input:
Which particle type can be identified as being from a specific element?  
 (A) electron (B) atom (C) neutron (D) proton

Ex Output:
B


Ex Input:
During which process are pieces of rock material being moved over Earth's surface by water and wind?  
 (A) conduction (B) deposition (C) erosion (D) revolution

Ex Output:

C