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:
The prairie grass ecosystem once had a deep layer of topsoil which was protected by the grasses that covered it. Removal of these grasses for farmland is causing the soil to be eroded mainly by  
 (A) wind and rain. (B) animal movement. (C) crops grown in the soil. (D) increased temperatures.

Ex Output:
A


Ex Input:
Florida has a large supply of phosphate that ancient seas deposited millions of years ago. The phosphate contains the remains of animals that were deposited in layers on the sea floor. Which type of rock did the phosphate become?  
 (A) intrusive igneous (B) extrusive igneous (C) clastic sedimentary (D) organic sedimentary

Ex Output:
D


Ex Input:
Which of the following is an example of heat transfer by conduction?  
 (A) a whole metal spoon getting hot when one end is in hot soup (B) the inside of a car in the sun getting very hot (C) a tar road getting hotter in the sun than a concrete sidewalk (D) a fireplace fire heating a room on a cold day

Ex Output:

A