The correct answer is A. CnH2n + 2.
A saturated hydrocarbon is an alkane, which is a hydrocarbon that contains only single bonds between carbon atoms. The general formula for an alkane is CnH2n + 2, where n is the number of carbon atoms in the molecule.
Option B, CnH2n – 2, is the general formula for an alkene, which is a hydrocarbon that contains one or more double bonds between carbon atoms.
Option C, CnH2n + 1, is the general formula for an alkyne, which is a hydrocarbon that contains one or more triple bonds between carbon atoms.
Option D, CnH2n – 1, is not the general formula for any type of hydrocarbon.