Final answer:
The correct answer to the question is (c) Two, as disaccharides are composed of two monosaccharide units, each forming a ring structure.
Step-by-step explanation:
The question asks about the number of rings in disaccharides. Disaccharides are carbohydrates formed by the combination of two monosaccharides. Monosaccharides can exist in ring-shaped molecules in aqueous solutions. When two of these monosaccharides bind through a glycosidic bond, the result is a disaccharide consisting of two rings. Examples include maltose, sucrose, and lactose, each with two monosaccharide units forming two rings. Therefore, the correct answer to the question is (c) Two.