How Do Allolactose and Lactose Differ

Multiple Choice

How do allolactose and lactose differ?

A) They are composed of different sugars.
B) Allolactose has a negative charge, while lactose has a positive charge.
C) The type of linkage holding the two constituent sugars together differs between lactose and allolactose.
D) The order of the sugars is reversed in the two molecules.
E) The constituent sugars are both upside down in lactose and right-side-up in allolactose.