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]: In a northern state, a room used for growing plants is not allowing enough light to enter for healthy plant growth. Adding windows in walls facing which direction would best solve this problem?  
 (A) north (B) south (C) east (D) west
[EX A]: B

[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]: The Davis Mountains in West Texas used to be taller than they are now. Which of the following conditions most likely caused the mountains to become shorter over time?  
 (A) Heat and pressure (B) Soil deposition (C) Rain and wind (D) River formation
[EX A]:
C