The correct option is A Rhodospirillum
Anoxygenic photosynthesis or photosynthesis in which oxygen is not released, is seen in Rhodospirillum, a purple non-sulphur bacteria.
Spirogyra, Chlamydomonas and Ulva are green alga and similar to green plants carry out oxygenic photosynthesis (photosynthesis in which oxygen is generated as a byproduct) to trap solar energy in a chemical form.