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 is an example of a form of electrical energy?
(A) lightning (B) windmill (C) radio waves (D) sound waves
[EX A]: A

[EX Q]: All of the different organisms interacting in a pond make up
(A) a community (B) a population (C) the water cycle (D) the habitat
[EX A]: A

[EX Q]: Which is an example of metamorphosis?
(A) A caterpillar changes into a butterfly. (B) An earthworm tunnels through the soil. (C) A lizard lays eggs in the sand. (D) A giraffe eats leaves from a tree.
[EX A]:
A