The correct options are
B V.D= Molarmass2
C V.D= Mass of N molecules of gasMass of N molecules of H2
D V.D= Mass of 1 molecule of gasMass of 1 molecule of H2
Vapour Density of a gas =DensityofthegasDensityofhydrogen
=MassofcertainvolumeofthegasatSTPMassofthesamevolumeofH
=MassofnmoleculesofthegasMassofnmoleculesofH2
=Massof1moleculeofthegasMassof1molecule(or2atomsofH)ofhydrogengas
=Molecularmass2
Hence the correct options are A, B and C.