The answer is A i believe. If not, i have no idea.
I would say that it comes from rain overtime
Answer: C) gas bubbles
Explanation:
An abiotic factor is the factor which influence the life of living beings on earth. The formation of gas bubbles inside the swamp is the example of abiotic factor.
The gas bubbles are formed inside the swamp, marsh or bog. It consists of the mixture of hydrogen sulfide, carbon dioxide and methane. These gases produce naturally in these water bodies due to anaerobic digestion and fermentation of the animal or plant matter inside the water body which results in the formation of bubbles in the body of water.