Answer: D
Explanation:
They form from Coal under high high pressure and many many years
Pesticides. They are known to be helpful for getting rid of pests and insects, but are also known to harm wildlife.
Since we have a hydrocarbon (CH4) plus Oxygen gas (O2) in the reactants and Carbon dioxide (CO2) and Water (H2O) we know that this type of reaction is considered a Combustion reaction.