Cellulose is a polymer of

Glucose

The answer is (1) glucose.

Cellulose is a polysaccharide, which means that it is a long chain of sugar molecules. The sugar molecules in cellulose are all glucose molecules, which are linked together by glycosidic bonds.

Fructose, ribose, and sucrose are all sugars, but they are not the same as glucose. Fructose is a ketose sugar, ribose is a pentose sugar, and sucrose is a disaccharide made up of glucose and fructose.