The nitrogen cycle is one of the most important biogeochemical cycle. It is an essential gas present in the atmosphere.
It is vital for the growth of plants and animals. Animals derive this nutrient by eating plants. But plants cannot take it in the form of nitrogen gas it takes it in different forms.
This is because the nitrogen fixing bacteria fixes nitrogen which means it converts nitrogen in the form which can be used by the plants.
So, the correct answer is nitrogen cycle as it needs to be modified before being used by plants.
I would say C. Since the material is getting warmer, the atoms and molecules will start to move fasten and then also create more "messiness" (which is entropy with a less-nice word)
