Q. Consider the following:
1.Decay of organic material 
2.Digestion of food by cattle
3.Agricultural activities
Which of the above are the sources of methane?

[A] 1, 3 and 4 only

[B] 2, 3 and 4 only

[C] 1, 2 and 4 only

[D] 1, 2, 3 and 4

Answer: D

Explanation – Some of the sources of methane are – decay of organic materials, cattle, agricultural activities, wildfires, wetlands, gas hydrates, termites, oceans, freshwater bodies, etc.

Source: Business Standard