You are given a science question (hard-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]: What is the most likely outcome of the Moon moving away from Earth?
(A) A lunar day is shorter. (B) A lunar eclipse lasts longer. (C) Earth moves closer to the Sun. (D) Earth's tides decrease in size.
[EX A]: D

[EX Q]: Which question will best help a student determine the composition of an unknown substance?
(A) Is the sample warm or cold? (B) How valuable is the sample? (C) Has the sample ever been melted? (D) Does the sample conduct electricity?
[EX A]: D

[EX Q]: What kind of energy change occurs when a battery is operating a remote control toy?
(A) Heat energy is changed to light energy. (B) Light energy is changed to heat energy. (C) Potential energy is changed to kinetic energy. (D) Kinetic energy is changed to chemical energy.
[EX A]:
C