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.

[EX Q]: Which set contains kingdoms that contain only heterotrophs?   
 (A) Protists, Fungi (B) Bacteria, Animals (C) Plants, Fungi (D) Animals, Fungi
[EX A]: D

[EX Q]: The teacher heats a pot of water. Once the water reaches 100°C, which point has the water reached?  
 (A) boiling (B) melting (C) freezing (D) evaporating
[EX A]: A

[EX Q]: Which of these must occur when a substance goes through a chemical change?  
 (A) The substance gets larger. (B) The substance changes phases. (C) The substance changes shape. (D) The substance forms a new substance.
[EX A]:
D