The incorrect statement from the following with respect to carbohydrates is:

All monosaccharides are reducing sugars.

The monosaccharide units obtained from hydrolysis of oligosaccharides are always the same.

Starch and cellulose are typical examples of polysaccharides, which are very high molecular weight compounds of more than ten monosaccharide units.

Open chain and cyclic structures co-exist at equilibrium that are responsible for certain properties as in the case of D-(+)-glucose.