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: The body is made up of many systems that interact with one another. For example, the skeletal system and the muscular system work together to help the body move. Which system works with the respiratory system to distribute oxygen to the body?  
 (A) muscular system (B) digestive system (C) lymphatic system (D) circulatory system

Output: D


Input: Consider Input: During which season of the year would a rabbit's fur be thickest?  
 (A) fall (B) spring (C) summer (D) winter

Output: D


Input: Consider Input: Which is a feedback mechanism the human body uses to maintain homeostasis?  
 (A) copying genetic material during cell division (B) rejecting a flu vaccine by the immune system (C) perspiring to lower the body temperature (D) learning a new behavior to survive in a new environment


Output: C