What is not a way in which prokaryotes are useful to humans?

A. To synthesize drugs

B. To form a symbiotic relationship and obtain ammonia

C. To produce foods such as yogurt

D. None of the choices

The correct answer is option D, None of the choice.

Prokaryotes like Escherichia coli are used in drug production. Rhizobium bacteria (prokaryotes) in the soil, form symbiotic relationship with the roots of the plant to fix nitrogen. And prokaryotes are measured in terms of colony-forming units (CFU) of bacteria to produce nutritious yoghurt.