Concept: The carbon cycle includes processes that return carbon to the atmosphere, and combustion is one such process.
Explanation:The carbon cycle describes how carbon moves between the atmosphere, living organisms, oceans, and the Earth's crust.
Combustion occurs when organic materials like wood, coal, oil, or gas burn in the presence of oxygen.
This burning releases carbon dioxide gas (
CO2) into the atmosphere.
Thus, combustion directly adds carbon to the air and is an important part of the carbon cycle.
Nitrification is the conversion of ammonia (
NH3) into nitrites and nitrates, so it belongs to the nitrogen cycle.
Evaporation and transpiration mainly involve water movement, not carbon movement.
Therefore, the process from the list that takes place in the carbon cycle is combustion.
Answer: C. Combustion