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]: A snail's shell provides the snail with
(A) food. (B) energy. (C) protection. (D) transportation.
[EX A]: C

[EX Q]: Which of these elements is found in the greatest amount in organisms?
(A) carbon (B) iron (C) lead (D) neon
[EX A]: A

[EX Q]: Earth orbiting the Sun causes
(A) the changing of the seasons. (B) daily tidal cycles. (C) day to become night. (D) the phases of the Moon.
[EX A]:
A