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]: Shale is a sedimentary rock that can be metamorphosed into slate by  
 (A) cementation. (B) chemical weathering. (C) sedimentation. (D) increased pressure.
[EX A]: D

[EX Q]: Which is most likely a genetic adaptation of desert plants to survive the hot, dry climate conditions?  
 (A) thin bark (B) waxy leaves (C) leaves that remain all year (D) flowers that bloom all year
[EX A]: B

[EX Q]: When rocks are exposed to wind, rain, heat, ice, or waves, the rocks  
 (A) fold. (B) erode. (C) contract. (D) melt.
[EX A]:
B