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]: Some plant species are more tolerant of acidic soil than others. The tolerant species are favored in areas affected by which consequence of human activity?  
 (A) mixing of pollutants with rain (B) erosion of topsoil by clearcutting (C) runoff of fertilizer used in farming (D) thinning of the atmospheric ozone layer
[EX A]: A

[EX Q]: Which two things interact most in the water cycle?  
 (A) oceans and the Moon (B) oceans and the Sun (C) lakes and the Moon (D) lakes and the Sun
[EX A]: B

[EX Q]: Which did Thomas Edison invent?  
 (A) microscope (B) compass (C) light bulb (D) steam engine
[EX A]:
C