Question

Which of the following correctly describes a reaction that forms a disaccharide from two monosaccharides?
Answer
Galactose + glucose → lactose
Glucose + sucrose → fructose
Glycogen + fructose → maltose
Maltose + lactose → cellulose

Answer 1

The answer that correctly describes a reaction that forms a disaccharide from two monosaccharides is Galactose + glucose = lactose. 
Cellulose is not a disaccharide, glycogen is not a monosaccharide, and sucrose isn't either.