Lactose found in milk is a disaccharide composed of

The correct option is Galactose and glucose.

Lactose is a disaccharide, which is a type of carbohydrate formed when two monosaccharides (simple sugars) are joined together by a glycosidic linkage.
In the case of lactose, which is the primary sugar found in milk, the two constituent monosaccharide units are:
1. D-galactose
2. D-glucose

These two simple sugars are chemically bonded via a β-1,4-glycosidic bond. During the formation of this bond, a condensation reaction occurs where a molecule of water (H₂O) is released.
Therefore, when lactose is hydrolyzed (broken down) by the enzyme lactase, it yields one molecule of galactose and one molecule of glucose.