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]: Evidence of organisms that lived on Earth a long time ago would most likely be found in  
 (A) crystals. (B) lava. (C) sedimentary rock. (D) metamorphic rock.
[EX A]: C

[EX Q]: If an ecosystem's balance is disturbed by a volcanic eruption, what will most likely occur?  
 (A) The ecosystem will not change from its original state. (B) The ecosystem will eventually become balanced again. (C) The consumers in the ecosystem will begin to consume carbon dioxide. (D) The consumers in the ecosystem will begin to produce more oxygen.
[EX A]: B

[EX Q]: Beans and coal both have stored energy. Where did the energy come from that is stored in beans and coal?  
 (A) From the Earth's gravity (B) From the Sun's light (C) From the heat in the Earth's core (D) From the air's carbon dioxide
[EX A]:
B