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.

[Q]: Which lists the diameter of the planets in order from smallest to largest?
(A) Venus, Earth, Mercury, Mars (B) Earth, Mars, Venus, Mercury (C) Mars, Mercury, Earth, Venus (D) Mercury, Mars, Venus, Earth
[A]: D

[Q]: Compost piles have many parts, such as leaves, moisture, vegetables, and microorganisms. Which part of a compost pile breaks down materials and adds nutrients to the soil?
(A) leaves (B) moisture (C) vegetables (D) microorganisms
[A]: D

[Q]: Which statement best describes the organization of the Periodic Table of the Elements?
(A) All gases are grouped together. (B) Gases easily form compounds with other elements. (C) Elements within a group have similar properties. (D) Elements within a period have the same number of electrons.
[A]:
C