Assertion :Deforestation is one main factor contributing to global warming. Reason: Besides $C{O}_2$, two other gases methane and CFCs are also included under greenhouse gases.

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
Deforestation results in an increase in greenhouse gases which retains more and more UV radiations and leads to global warming. Global warming is the warming/heating up of the earth's atmosphere. Greenhouse gases are the gaseous compound in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere. There are four main gases are methane, CFCs, carbon dioxide, and nitrous oxides.

Therefore, the correct answer is option B.