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]: Proxima Centauri is the closest star to the Sun. Which units do astronomers most often use for the distance between Earth and Proxima Centauri?  
 (A) miles (B) meters (C) light years (D) astronomical units
[A]: C


[Q]: Which location on Earth receives the most direct sunlight?  
 (A) the deserts (B) the South Pole (C) the equator (D) the Western Hemisphere
[A]: C


[Q]: Which two processes could result in the formation of high mountains with well-rounded peaks?  
 (A) volcanic eruptions and global warming (B) earthquakes and tidal activity (C) collision of crustal plates and erosion (D) production of greenhouse gases and weathering
[A]:
C