Correct option is B
Correct answer: B (Only (A)-(F) and (B)-(D))
Correct combinations
(A) + (F)
Carbon dioxide was recognized as a gas different from other gases.
Meaningful and grammatically correct.
(B) + (D)
India has signalled a commitment to clean energy with ambitious targets.
Meaningful and grammatically correct.
Incorrect combinations
(A) + (D)
Carbon dioxide was recognized clean energy with ambitious targets.
Incorrect and meaningless.
(C) + (E)
India’s literacy and financial literacy levels by both fermentation and combustion
Incorrect and illogical.
(B) + (E)
India has signalled a commitment to by both fermentation and combustion
Incorrect structure.
(B) + (F)
India has signalled a commitment to as a gas different from other gases
Incorrect and meaningless.
(A) + (E)
Carbon dioxide was recognized by both fermentation and combustion
Incorrect in this context; incomplete and logically weak compared to (A)+(F)
Final conclusion
Only (A)-(F) and (B)-(D) form correct meaningful sentences.
Therefore, the correct option is B.