Concept:Disaccharides are carbohydrates made of two monosaccharide units linked by a glycosidic bond.Explanation:Maltose consists of two glucose units.Lactose consists of glucose and galactose units.Both are disaccharides.Starch and glycogen are polysaccharides (many sugar units).Glucose and galactose are monosaccharides (single sugars).Ribose and xylose are also monosaccharides.Only maltose and lactose match the definition of disaccharides.Answer:C. Maltose and lactose