Assertion (A):
Scientists observed that a few bacteria can grow in sulfur-rich environments and perform photosynthesis. These bacteria can split H₂S and release sulfur.
Reason (R):
The above assertion provides evidence that during photosynthesis in green plants, oxygen is released by splitting of water.

Correct option is A

Correct Answer: (a)
Explanation:
(A) is true because purple and green sulfur bacteria perform photosynthesis using H₂S instead of water, releasing sulfur.
(R) is also true: in green plants, O₂ is released from water, not from CO₂.
However, (R) does not explain why sulfur bacteria produce sulfur; thus R is not the correct explanation of A.
Information Booster:
Bacterial photosynthesis occurs without oxygen production (anoxygenic).
Green plants produce oxygen from water photolysis (oxygenic photosynthesis).
Discovery helped differentiate between two forms of photosynthesis.
H₂S replaces H₂O as electron donor in sulfur bacteria.
Evolutionary evidence suggests early photosynthesis was anoxygenic.
Additional Information (Incorrect Options):
(b) Incorrect: R is true.
(c) Incorrect: Both A and R are true.
(d) Incorrect: R does not explain A.