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]: Some events on Earth happen instantly while others take thousands of years to occur. Which process takes the longest time to complete?  
 (A) rivers rising due to storms and floods (B) evaporation of water from the leaves of a plant (C) weathering of a rock to form small rocks and sand (D) movement of small pieces of rock by flowing water
[A]: C


[Q]: When microorganisms deplete the oxygen in soil through respiration, the soil becomes  
 (A) humus. (B) anaerobic. (C) compost. (D) aerobic.
[A]: B


[Q]: In the 16005 Robert Hooke invented an improved type of microscope. Which of these was a direct result of this invention?  
 (A) The first view of atoms and molecules (B) Detailed observations of Jupiter and Mars (C) The name spectrum for the colors of light (D) The term cell to describe the smallest unit of life
[A]:
D