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: When iron combines with oxygen in a moist environment, rust forms because of a  
 (A) chemical reaction. (B) physical reaction. (C) change in density. (D) change in temperature.

Answer: A


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

Answer: A


Question: Temperature is the measurement of which type of energy?  
 (A) chemical (B) mechanical (C) potential (D) kinetic

Answer:
D