The correct option is A Glucose
Most common monomer used in polysaccharides is glucose. For example, starch, cellulose, glycogen all are polymers derived from glucose. Plants synthesize carbohydrates as glucose or fructose and store in other form like starch. The type of linkage between glucose molecules is different in storage and structural polysaccharides. The linkage in storage polysaccharides is α- whereas β-linkage is present between glucose molecules in structural polysaccharides.