Answer:
The correct answer is an option - Factories.
Explanation:
The nitrogen cycle is a biogeochemical process in which nitrogen is turned into several types of chemical forms as it moves in between the atmosphere, geosphere, and biosphere.
Nitrogen cycle involves both biological and chemical process. The biological process involves nitrogen fixation with the help of the bean plants with nodules and from dead plants and animals. Lightning is also helpful in the nitrogen cycle.
Thus, the correct answer is option - factories.
