Allolactose Is an Important Molecule in Regulation of the Lac $\beta$

Allolactose is an important molecule in regulation of the lac operon. How does allolactose differ from lactose?

A) Lactose contains galactose and glucose, while allolactose contains two glucose units.
B) Lactose is a reducing sugar, while allolactose is not.
C) Lactose contains a $\beta$ -glycosidic bond, while allolactose contains an $\alpha$ -glycosidic bond.
D) Lactose contains a 1 $\rightarrow$ 4 glycosidic bonds, while allolactose contains a 1 $\rightarrow$ 6 glycosidic bond.
E) None of these statements describes differences between lactose and allolactose.