Which of the following names describes lactose?Group of answer choicesO-α-D-galactopyranosyl-[1→4]-D-glucopyranoseO-β-D-galactopyranosyl-[1→4]-D-glucoseO-α-D-galactopyranosyl-[1→4]-D-glucoseO-β-D-glucopyranosyl-[1→4]-D-galactoseO-β-D-galactopyranosyl-[1→2]-D-glucose

The correct name that describes lactose is O-β-D-galactopyranosyl-[1→4]-D-glucose.

Here's why:

Lactose is a disaccharide sugar that is found in milk. It is composed of two sugar molecules, galactose and glucose, linked together.

The "O-β-D-galactopyranosyl-[1→4]-D-glucose" name indicates that it is a beta-linked disaccharide, meaning the glycosidic bond is in the beta configuration. This is correct for lactose.

The "[1→4]" indicates that the bond is between the 1st carbon atom of the galactose molecule and the 4th carbon atom of the glucose molecule, which is also correct for lactose.

The "galactopyranosyl" and "glucose" parts of the name indicate the two sugar molecules that make up lactose, which are galactose and glucose.

So, the name "O-β-D-galactopyranosyl-[1→4]-D-glucose" correctly describes the structure and composition of lactose.