3. Which statement related to Gram-negative photosynthetic bacteria is correct?
(A) Cyanobacteria use hydrogen (H2) or water as photosynthetic electron donors.
(B) Green sulfur and purple nonsulfur bacteria undergo oxygenic photosynthesis.
(C) Aerobic photolithoautotrophs are the general metabolic type of cyanobacteria.
(D) Chlorophyll a and phycobiliproteins are the major photosynthetic pigments forpurple sulfur bacteria.
(E) Sulfur deposition is outside of purple sulfur bacteria and inside of green sulfurbacteria.