**Core Concept**
Alginates are a type of polysaccharide derived from brown seaweed, primarily used as a thickening agent and in the treatment of acid reflux and peptic ulcers. They work by forming a protective barrier over the mucosa, preventing acid and pepsin from coming into contact with the gastric lining.

**Why the Correct Answer is Right**
Alginates contain a high concentration of guluronic acid, which is responsible for their ability to form a gel-like substance when mixed with water. This gel-like substance coats the gastric mucosa, preventing the backflow of stomach acid into the esophagus and reducing symptoms of acid reflux. Alginates also have a mild buffering capacity, which helps to neutralize stomach acid.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the primary function of alginates.
**Option B:** This option is incorrect because it is not a recognized property of alginates.
**Option C:** This option is incorrect because it is not a common use of alginates.

**Clinical Pearl / High-Yield Fact**
Alginates can be used in combination with antacids to provide rapid relief from heartburn and acid reflux symptoms. They are also useful in patients with esophageal strictures or those who are undergoing endoscopy with sedation.

**Correct Answer: C. Antacids.