instruction:
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.
question:
The moon goes through phases as it revolves around Earth. During which phase of the moon would it be possible for a solar eclipse to occur?  
 (A) new moon (B) full moon (C) waning (D) waxing
answer:
A


question:
Scientists wonder how the Egyptian pyramids were built. They think that the huge blocks of stone may have been put into place by pushing them up a sloping pathway. The pathway is which type of simple machine?  
 (A) lever (B) pulley (C) inclined plane (D) wheel and axle
answer:
C


question:
The magnetic poles of Earth frequently change location. What is the direct cause of this change in magnetic pole location?  
 (A) molten rock flowing in the asthenosphere (B) convection cells in the lower mantle (C) turbulence in the liquid outer core (D) radioactive decay in the solid inner core
answer:

C