Q. Which of the following are sources of methane emission?

1. Wetlands
2. The raising of livestock
3. The treatment of wastewater

Select the correct option from the codes given below:
Answer: 1, 2 & 3
Notes: Methane is emitted from both natural and anthropogenic sources. Wetlands are the largest natural source of methane. The raising of livestock produces methane via enteric fermentation, while wastewater treatment releases methane due to anaerobic decomposition of organic matter. Thus, all three are significant sources of methane emission.