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: What happens at the boiling point of a substance?  
 (A) liquid becomes a gas (B) solid becomes a gas (C) liquid becomes a solid (D) solid becomes a liquid

Answer: A


Question: Genes are located on chromosomes which are composed of  
 (A) DNA. (B) RNA. (C) ATP. (D) ADP.

Answer: A


Question: A certain disease of the spinal cord can be passed on from a dog to its offspring. This disease can result in the dog's muscles becoming weak, leading to paralysis. This is an example of  
 (A) an infectious disease. (B) a respiratory disease. (C) an inherited disease. (D) an environmental disease.

Answer:
C