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 of these substances is correctly identified as a mineral?  
 (A) coal (B) quartz (C) granite (D) sandstone
[EX A]: B

[EX Q]: A class made a solar cooker out of a large can. What color should they paint the can in order to collect the most heat?  
 (A) black (B) green (C) pink (D) white
[EX A]: A

[EX Q]: Which will most likely happen to a solid substance that is heated?  
 (A) It will melt. (B) It will boil. (C) It will harden. (D) It will evaporate.
[EX A]:
A