**Core Concept**
The question tests knowledge of **mucopolysaccharides** with **anticoagulant properties**, specifically focusing on their role in preventing blood clot formation. Mucopolysaccharides, also known as glycosaminoglycans, are long chains of sugar molecules found throughout the body.

**Why the Correct Answer is Right**
The correct answer is related to **heparin**, a well-known **anticoagulant** used to prevent and treat blood clots. Heparin is a type of **mucopolysaccharide** that enhances the activity of **antithrombin**, a protein that inhibits the coagulation cascade, thereby preventing clot formation.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it does not have significant anticoagulant properties.
**Option B:** Incorrect as it is not primarily known for its anticoagulant action.
**Option C:** Incorrect because, although it is a mucopolysaccharide, it is not the one with the most notable anticoagulant effect.

**Clinical Pearl / High-Yield Fact**
Remember that **heparin** is often used in clinical settings to prevent deep vein thrombosis and pulmonary embolism, making it a crucial **anticoagulant** in patient care.

**Correct Answer:** D. Heparin