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.

Input: Consider Input: Which body systems are most involved in the response when someone stubs his or her toe?
(A) nervous and muscle (B) muscle and endocrine (C) nervous and digestive (D) reproductive and circulatory

Output: A

Input: Consider 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.

Output: A

Input: Consider Input: Robots are used to help manufacture cars. One problem with this is
(A) less waste. (B) lower cost. (C) fewer jobs. (D) more mistakes.
Output: C