Residence time of methane in the atmosphere is___________________?
A. 3 – 7 days
B. 2 -3 days
C. 3 – 7 years
D. 2 – 3 years
A. 3 – 7 days
B. 2 -3 days
C. 3 – 7 years
D. 2 – 3 years