Biology

The correct answer is: They do not produce oxygen.

Other photosynthetic prokaryotes, such as purple sulfur bacteria and green sulfur bacteria, perform anoxygenic photosynthesis. Unlike cyanobacteria, which use water as an electron donor and produce oxygen as a byproduct, these bacteria use alternative electron donors like hydrogen sulfide (H₂S) or organic molecules. As a result, they do not produce oxygen during photosynthesis.

The other options are incorrect:

Option B: This is incorrect. All photosynthetic organisms, including cyanobacteria and other photosynthetic prokaryotes, us...