**Core Concept**
Protamine is a positively charged polypeptide used to reverse the anticoagulant effects of heparin, a highly sulfated glycosaminoglycan with a strong negative charge. The reversal of heparin's anticoagulant activity is based on the electrostatic interaction between protamine and heparin, which binds to and neutralizes heparin's anticoagulant activity.

**Why the Correct Answer is Right**
The interaction between protamine and heparin is based on the principle of charge neutralization. Heparin, being a highly sulfated glycosaminoglycan, has a strong negative charge, while protamine has a strong positive charge. The binding of protamine to heparin results in the formation of a stable complex that effectively neutralizes heparin's anticoagulant activity. This is achieved through the electrostatic interaction between the positively charged arginine and lysine residues of protamine and the negatively charged sulfate groups of heparin.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the mechanism of protamine antagonism for heparin.
**Option B:** This option is incorrect because it suggests a different mechanism of action for protamine that is not supported by scientific evidence.
**Option C:** This option is incorrect because it does not accurately describe the effect of protamine on heparin's anticoagulant activity.

**Clinical Pearl / High-Yield Fact**
It is essential to note that protamine can cause anaphylaxis in some patients, particularly those with a history of allergies or sensitivities. A test dose of protamine is often administered before the full dose to assess for any allergic reactions.

**Correct Answer: B. Protamine binds to and neutralizes heparin's anticoagulant activity through electrostatic interactions.**