The correct option is D All of above.
The monohalogen derivatives of alkanes are called as alkyl halides denoted as R−X where (R−) is the alkyl group and X− is the halogen atom. The common name of an alkyl halide is always written as two separate words. In IUPAC system, the monohalogen derivatives of alkanes are named as haloalkanes. for e.g., methyl chloride has IUPAC name chloromethane.