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 action involving a pulley system requires the least amount of force?
(A) using several pulleys together instead of a single pulley (B) using a fixed pulley instead of a moveable pulley (C) pulling a long rope instead of a short rope (D) pulling a rope up instead of down
[A]: A

[Q]: A model of the Moon would be different from a model of Earth in that the Moon should
(A) be smaller than Earth. (B) have a source of light inside. (C) have a smoother surface than Earth. (D) have fewer impact craters on the surface.
[A]: A

[Q]: An apple appears red when struck by white light. This appearance is because the red light is reflected and the other colors are absorbed. What color will this apple appear to be when struck by blue light?
(A) black (B) blue (C) red (D) white
[A]:
A