A disaccharide is formed when two monosaccharides join. Which of the following is a disaccharide?

Glucose and lactoseGlucose and maltoseGlucose and fructose

The correct answer is: Glucose and fructose

Glucose and fructose are monosaccharaides that are joined by glycosidic linkage to form sucrose. This disaccharaides are produced naturally in plants but for human production it is is extracted, and refined, from sugar cane.

Lactose and maltose are also disaccharides. Lactose is composed of galactose and glucose, while maltose from consists of two units of glucose that are joined with an α (1→4) glycosidic bond.