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.

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

A: D
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Q: One hot summer, a grassland experienced a drought. Which most likely happened in the ecosystem during this time?  
 (A) The competition for food among primary consumers increased. (B) Nutrients cycled through the system at a faster rate. (C) Less solar radiation was able to enter the system. (D) Secondary consumers became extinct.

A: A
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Q: When an earthquake occurs, the speed of the seismic waves changes as they  
 (A) move through different materials. (B) are pulled by the force of gravity. (C) lose energy to surrounding rocks. (D) reflect off of boundaries.

A:
A
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