A) A-Sludge, B-Dung + water, C-$CH_{4} + CO_{2}$
B) A-Dung + water, B-Sludge, C-$CH_{4} + CO_{2}$
C) A-Sludge, B-$\ CH_{4}$ and $CO_{2}$, C-Dung + water
D) A-$CH_{4} + CO_{2}$, B-Dung + water, C-Sludge
Explanation
The correct answer is Option C: A-Sludge, B-$\ CH_{4}$ and $CO_{2}$, C-Dung + water.
A detailed explanation for this question is being prepared.