Correct Answer: D-Galacturonic acid

Solution : The correct option is D-galacturonic acid.

Pectin, a complex carbohydrate found in the cell walls of plants, is primarily composed of galacturonic acid units. These units are linked together to form a polymer. Pectin is a common ingredient in food processing, especially when producing jams, jellies and other preserves. It gives fruits their gel-like consistency.