Which of the following carbohydrates is a monosaccharide?

• A. Starch
• B. Glycogen
• C. Glucose
• D. Cellulose

Answer: (C)

Monosaccharides are the simplest carbohydrates, consisting of a single sugar unit such as glucose. The other options are polysaccharides—long chains built from many sugar units. Starch and glycogen are storage polysaccharides made up of glucose units linked together in different ways, while cellulose is a structural polysaccharide in plant cell walls with a different type of linkage that gives rigidity. Glucose is the basic monosaccharide unit, the simplest form of carbohydrate, so it is the correct choice.