Q. Which of the following is/are the sources of methane?
1. Wetlands
2. Livestock
3. Wildfires
Select the correct answer using the codes given below:

[A] 1 only

[B] 1 and 2 only

[C] 2 and 3 only

[D] 1, 2 and 3

Answer: D
Notes:

Methane (CH4) is emitted by natural sources such as wetlands, as well as human activities such as leakage from natural gas systems and the raising of livestock.  

Smaller sources include termites, oceans, sediments, volcanoes, and wildfires. 

Source: Shankar