Assertion (A): Deforestation is one main factor contributing to global warming.
Reason (R) : Besides `CO_(2)`, two other gases methane and CFCs are also included under greenhouse gases:
A. If both assertion and reason are true and the reason is the correct explanation of the assertion
B. If both assertion and reason are true but reason is not the correct explanation of the assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false.
