Answer:
The correct answer is D. On the plasma membrane.
Explanation:
Prokaryotes do not have mitochondria to synthesize ATP but ATP synthesis takes place in prokaryotes on the plasma membrane as the plasma membrane contains the enzymes that are required for ATP synthesis.
The process of ATP synthesis is just like in the mitochondria. NADH helps in building the proton gradient in the outer portion of the membrane by the help of electron carriers embedded in the plasma membrane. Then these protons come back in the cytoplasm through ATP synthase enzyme complex.
This entry of protons helps in the generation of ATP from ADP and inorganic phosphate with the help of ATP synthase enzyme. Therefore the correct answer is D. On the plasma membrane.
