Lactose is made of

Options

A. `alpha`-D-glucose only
B. `alpha`-D-glucose and `beta-D`-glucose
C. `alpha`-D-galactose and `beta`-D-glucose
D. `beta`-D-galactose and `beta`-D-glucose

Answer

D

Explanation

Lactose (milk sugar) is a disaccharide, obtained by the condensation of one molecule of `beta`-D galactopyranose and one molecule of `beta`-D-glucopyranose.