instruction:
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.
question:
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.
answer:
A


question:
Which two behaviors best demonstrate stewardship?  
 (A) reducing consumption, recycling wastes (B) increasing consumption, discarding wastes (C) reducing consumption, discarding wastes (D) increasing consumption, recycling wastes
answer:
A


question:
Which is not a type of electromagnetic wave?  
 (A) sound wave (B) x-ray (C) microwave (D) radio wave
answer:

A