Which one of the statements is correct in relation to monosaccharides? A. They are simple sugars B. Cellulose is an example of monosaccharide C. They are the chief energy source D. They are made up of ten or more sugar molecules

Correct option is B

Monosaccharides are the simplest form of carbohydrates, consisting of a single sugar unit, hence statement A is correct.
Glucose, a monosaccharide, is the primary energy source in most living organisms. Therefore, statement C is also correct.
Cellulose is not a monosaccharide; it is a polysaccharide made up of many glucose monomers linked by β-1,4-glycosidic bonds. Hence, statement B is incorrect.
Monosaccharides are made up of a single sugar unit, not ten or more. Molecules made of ten or more sugar units fall under polysaccharides, not monosaccharides. Thus, statement D is incorrect.
Therefore, only statements A and C are correct, making option (b) the right choice.