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]: The main function of a fish's fins is to help the fish  
 (A) reproduce (B) see (C) breathe (D) move
[EX A]: D

[EX Q]: Earth is about 81 times more massive than the Moon. How will the mass and weight of a rocket on the Moon compare to its mass and weight on Earth?  
 (A) The mass and weight will be less on the Moon. (B) The mass and weight will be greater on the Moon. (C) The mass will be the same, but its weight will be less on the Moon. (D) The mass will be the same, but its weight will be greater on the Moon.
[EX A]: C

[EX Q]: A bicyclist rides on a flat road and then stops pedaling but does not apply the brakes. The bicycle stops because of ___.  
 (A) balance (B) friction (C) attraction (D) magnetism
[EX A]:
B