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]: The incompleteness of the fossil record results primarily from which phenomenon?  
 (A) the frequency and irregular timing of organism speciations (B) the metamorphosis of most sedimentary rock by heat and pressure (C) the geologically rapid cycling of crust material back into the mantle (D) the rarity with which organic remains are exposed to fossil-forming conditions
[EX A]: D

[EX Q]: A student pushes a box to slide it across the floor. Which statement explains why the box begins to move?  
 (A) The weight of the box is greater than the force of friction. (B) The weight of the box is less than the force of friction. (C) The applied force is greater than the force of friction. (D) The applied force is less than the force of friction.
[EX A]: C

[EX Q]: The formation of the Himalayan Mountains is one example of land features caused by compressive forces. Which action most likely led to the formation of these mountains?  
 (A) seafloor spreading (B) strike-slip faulting (C) colliding plates (D) hot spots
[EX A]:
C