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]: One method of heat distribution is a baseboard forced hot water system. A baseboard system carries hot water through a pipe that passes through many small, flat plates called fins. What is the purpose of these fins?
(A) to dissipate the heat of the hot water flowing through the pipe (B) to prevent the baseboard from coming in contact with hot surfaces (C) to replace the heated air leaving the system with cold air (D) to prevent dust and other particles from entering the baseboard
[EX A]: A

[EX 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
[EX A]: D

[EX Q]: Plants on hills keep dirt in place during a rain storm. Plant roots grow into the dirt and keep the dirt from moving. Why do roots grow into the dirt?
(A) to release gases (B) to release water (C) to absorb energy (D) to absorb nutrients
[EX A]:
D