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: Which unit is used to express the amount of energy in food?  
 (A) Calorie (B) degree Celsius (C) milliliter (D) gram

Output: A


Input: Consider Input: Which property supports the hypothesis that eukaryotic mitochondria were once prokaryotic organisms?  
 (A) They lack genetic material. (B) They lack a mechanism of motility. (C) They lack internal membrane-bound organelles. (D) They lack a need for proteins in their life functions.


Output: C