Which of these occurs through symbiotic nitrogen fixation?
the plant benefits from using an endless source of nitrogen.
the soil benefits from being naturally fertilized.
bacteria benefit from using photosynthates from the plant.
all of the above occur.

All of the above occur.

Explanation:

Symbiotic Nitrogen Fixation (BNF) is a natural process that occurs in combinations of plants with diazotrophic bacteria. Its main product, nitrogen, is an essential nutrient for plant growth and development. The nutrient is captured from the air and fixed by diazotrophic bacteria found in many soil types.  In the roots, noduliferous bacteria generally have high specificity for each plant species, being common, for example, the symbiosis between plants of the Leguminosae family and diazotrophic bacteria known as rhizobia.

This fixation process has many positive points, among which we can mention that in this process the plant benefits from the use of an infinite source of nitrogen, the soil benefits from being naturally fertilized and the bacteria from the photosynthesis of the plant. plant.

b.have there own function.