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.

[Q]: Which of the following best describes a mineral?  
 (A) a solid natural material with a crystal structure (B) a material that was once living but has decayed (C) a liquid chemical used to make soil more fertile (D) a nutrient produced by plants that other organisms need
[A]: A


[Q]: 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
[A]: C


[Q]: Condensation in the water cycle can best be described as the result of water vapor  
 (A) rising into the atmosphere, cooling and changing into a liquid form. (B) rising into the atmosphere, warming and changing into a gaseous form. (C) changing from a liquid form into a solid and forming snow. (D) changing from a gas form into a solid and forming hail.
[A]:
A