The correct options are
A LacY- β-galactosidase
C LacZ- lactose permease
The three major enzymes involved in the digestion of lactose in the human gut are β-galactosidase, β-galactoside transacetylase and lactose permease. These are produced by transcription of three structural genes of the lac operon of E.coli. Of these, the gene lacZ codes for the enzyme β-galactosidase, lacY codes for lactose permease and lacA codes for β-galactoside transacetylase.