What is the mechanism by which antithrombin III inhibits the coagulation cascade?

A By binding to and activating thrombin
B By binding to and inhibiting thrombin and other coagulation factors ✓
C By competing with heparin for binding sites on coagulation factors
D By activating protein C, which then inhibits coagulation factors

Explanation

Antithrombin III is a protease inhibitor that binds to and inhibits the activity of thrombin and other coagulation factors, thereby preventing excessive clot formation.

Source

Guyton and Hall Textbook of Medical Physiology
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Medium MEDICAL Confidence: high