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.

Auroras occur where Earth's magnetosphere traps high-energy particles in which region of the atmosphere?  
 (A) troposphere (B) stratosphere (C) thermosphere (D) exosphere
C

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
C

An example of a calcium carbonate deposit in the lithosphere is  
 (A) limestone. (B) granite. (C) gneiss. (D) shale.

A