Which of the following is a disaccharide? A. Sucrose

B. Fructose

C. Galactose

D. Glucose

A. Sucrose

That is because disaccharide is when sugars combine to form a water molecule.

A disaccharide is two monosaccharide groups chemically binded together. Glucose and galactose are monosaccharides (single sugar group)

Di - = 2

Saccharide = sugar

Fructose is a sucrose molecule bonded to a glucose molecule, and is therefore the disaccharide.