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]: What has occurred when bubbles form in a liquid that is being heated?  
 (A) Oxygen is absorbed from the air. (B) Heat is radiating in the liquid. (C) The boiling point has been reached. (D) Molecular stability in the liquid is increasing.
[A]: C


[Q]: Overuse of soil for farming causes local disruptions of several Earth subsystems. Which of these is a part of the biogeochemical cycle that experiences the most severe local disruption?  
 (A) release of carbon into the atmosphere (B) release of oxygen into the atmosphere (C) cycling phosphorus into the soil (D) cycling hydrogen into the soil
[A]: C


[Q]: Which term best describes the process responsible for cave formation that results from rock being dissolved by groundwater?  
 (A) chemical weathering (B) glacial movement (C) sedimentation (D) abrasion
[A]:
A