Nitrogen fixation is the process of converting atmospheric nitrogen (N2) into forms that can be used by living organisms. This process is essential for the growth and survival of plants and other living organisms.

Industries:
Industries can perform nitrogen fixation through a process called the Haber-Bosch process. This process involves combining nitrogen and hydrogen under high pressure and temperature to produce ammonia, which can then be used as a fertilizer.

Rhizobium:
Rhizobium is a type of bacteria that lives in the roots of leguminous plants. These bacteria have the ability to fix nitrogen from the air and convert it into a form that can be used by the plant. This process is called biological nitrogen fixation.

Lightning:
Lightning can also fix nitrogen in the atmosphere. The high energy of lightning can break the strong bonds between nitrogen molecules, allowing them to combine with oxygen and form nitrogen oxides. These nitrogen oxides can then dissolve in rainwater and be absorbed by plants.

All of the above:
All of the above options are correct. Nitrogen fixation can be performed by industries through the Haber-Bosch process, by bacteria such as Rhizobium through biological nitrogen fixation, and by lightning through atmospheric nitrogen fixation. Each of these processes plays an important role in providing the nitrogen necessary for the growth and survival of living organisms.

Nitrogen fixation is the process in which the atmospheric nitrogen is converted to the form which can be taken by the plants.