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]: A student is asked to bring something that feels rough to class. Which would be BEST for him to bring?  
 (A) Pillow (B) Marble (C) Sandpaper (D) Trading card
[EX A]: C

[EX Q]: The moon goes through phases as it revolves around Earth. During which phase of the moon would it be possible for a solar eclipse to occur?  
 (A) new moon (B) full moon (C) waning (D) waxing
[EX A]: A

[EX Q]: The Great Miami Aquifer is a large underground water supply that lies under much of southwest Ohio. The water level of the aquifer could be reduced over time by too much  
 (A) rainfall. (B) pollution. (C) irrigation. (D) evaporation.
[EX A]:
C