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: Which force produces energy as heat?  
 (A) pull (B) gravity (C) friction (D) magnetic

Answer: C


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: Which process is taking place when water freezes between cracks in rocks?  
 (A) deposition (B) weathering (C) sedimentation (D) crystallization

Answer:
B