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: Where do good bacteria grow to help keep people healthy?  
 (A) in the brain (B) in the blood (C) on the skin (D) on the bones

Answer: C


Question: The relationship between ticks and a dog can best be described as  
 (A) mutualism. (B) competition. (C) parasitism. (D) commensalism.

Answer: C


Question: Which of these is the main function of a cell wall?  
 (A) To make food (B) To store water (C) To provide support (D) To make the plant green

Answer:
C