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 phases of the Moon are daily changes in the appearance of the Moon. One reason Moon phases occur is because the Moon reflects sunlight. Which is another reason that the phases of the Moon occur?  
 (A) Earth is tilted on the axis. (B) The Moon rises and sets. (C) The Moon orbits Earth. (D) Earth orbits the Sun.
[EX A]: C

[EX Q]: A student walking quickly while carrying an orange on his lunch tray stops suddenly. The orange will most likely roll off the tray due to  
 (A) inertia of the orange. (B) centripetal force of the orange. (C) the friction acting on the orange. (D) the balanced forces acting on the orange.
[EX A]: A

[EX Q]: Why do two surfaces get warm when they are rubbed together?  
 (A) The surfaces absorb energy from the air. (B) Friction changes energy of motion to heat energy. (C) Moving objects produce heat energy. (D) Energy is transferred between the two surfaces.
[EX A]:
B