TASK DEFINITION: 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.
PROBLEM: Rocks that contain fragments of bones, shells, and plant remains are most likely  
 (A) crystals. (B) igneous. (C) sedimentary. (D) metamorphic.

SOLUTION: C

PROBLEM: Plants growing in a pond release a gas that fish need to survive. Which gas do the plants release that fish use?  
 (A) helium (B) hydrogen (C) nitrogen (D) oxygen

SOLUTION: D

PROBLEM: Drake has started a garden. What can Drake do to enrich the soil so that his plants will grow better?  
 (A) remove earthworms (B) add more water to the soil (C) increase the amount of pesticide he uses (D) mix decomposed plant matter into the soil

SOLUTION:
D