Which of the following statements is true regarding the mechanism of action of antithrombin III?

A It directly inhibits the activity of thrombin
B It enhances the activation of protein C
C It forms a covalent complex with thrombin, rendering it inactive ✓
D It competes with heparin for binding to thrombin

Explanation

Antithrombin III is a serine protease inhibitor that forms a covalent complex with thrombin, rendering it inactive and preventing further coagulation.

Source

Hematology: Clinical Principles and Applications
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Hard MEDICAL Confidence: high