instruction:
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:
Melting, boiling, and freezing are examples of  
 (A) physical changes. (B) chemical changes. (C) magnetic changes. (D) electrical changes.
answer:
A


question:
What gas in the air do we need to breathe in order to live?  
 (A) nitrogen (B) oxygen (C) carbon dioxide (D) hydrogen (E) water vapor
answer:
B


question:
The human body is made up of different levels of organization. A tissue is a group of cells that work together to perform a specific function. Which would be an example of a tissue in the human body?  
 (A) stomach (B) platelets (C) muscle (D) hair
answer:

C