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:
A student placed a small chip of limestone into a hydrochloric acid solution, and carbon dioxide gas was released. The carbon dioxide provided evidence that   
 (A) only a physical change occurred. (B) a chemical change occurred. (C) only a loss of mass occurred. (D) the formation of an element occurred.

Ex Output:
B


Ex Input:
Organisms contribute to the water cycle mainly through the process of  
 (A) irrigation. (B) evaporation. (C) precipitation. (D) transpiration.

Ex Output:
D


Ex Input:
What is happening when rocks are broken down by both physical and chemical changes?  
 (A) weathering (B) deposition (C) condensation (D) decomposing

Ex Output:

A