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]: Which of the following best represents one particular stage in a life cycle?
(A) a fish swimming (B) a seed sprouting (C) a leaf growing (D) a dog eating
[EX A]: B

[EX Q]: Carolina uses a microscope to view a soil sample taken from her backyard. Which part of the soil would she ONLY be able to see with a microscope?
(A) bacteria (B) grass (C) rainwater (D) rocks
[EX A]: A

[EX Q]: Which relationship is mutualistic?
(A) an insect that lives and feeds on the body of an alligator (B) an ant that lives on a plant and defends the plant from other insects (C) a bird that migrates to follow the movements of the butterflies that it eats (D) a deer that eats one kind of plant, which allows another kind of plant to grow in its place
[EX A]:
B