Which set of substances are monosaccharides?

• A. Glucose, Fructose, Galactose
• B. Sucrose, Lactose, Maltose
• C. Galactose, Sucrose, Fructose
• D. Glucose, Sucrose, Maltose

Answer: (A)

Monosaccharides are the simplest carbohydrates, consisting of a single sugar unit and cannot be broken down into smaller sugars by hydrolysis. Glucose, fructose, and galactose are all single-unit sugars, each a standalone sugar molecule. In contrast, the other groups are disaccharides, formed from two monosaccharide units linked together: sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (two glucose units). So the set with glucose, fructose, and galactose is the one that contains monosaccharides.