The correct path of events that take place in a nitrogen cycle is air, bacteria, plants and animals.
Answer: Option B
Step-by-step explanation:
Nitrogen forms the major proportion of air. The nitrogen in the atmosphere cannot be used as such by plants and animals. Thereby the atmospheric nitrogen is fixed in the soil by means of nitrogen fixing bacteria, these nitrogen fixing bacteria live in the root nodules of leguminous plants.
They maintain a symbiotic relation with plants through which they provide nitrogen to the plants. The animals take this fixed nitrogen from plants.