Which medication acts as a protective agent in treating gastric and duodenal ulcers?

Explanation

Among the listed options, carbenoxolone is known for its protective properties in managing gastric and duodenal ulcers by enhancing mucosal defense. H2 receptor antagonists like famotidine reduce acid secretion but do not directly protect the mucosa. Sodium bicarbonate neutralizes acid but lacks protective effects on ulcerated tissue.