What is the mechanism by which antithrombin III inhibits coagulation?

A By binding to and activating protein C
B By binding to and inhibiting thrombin
C By binding to and inhibiting factors Xa and IIa ✓
D By binding to and activating tissue factor pathway inhibitor

Explanation

Antithrombin III is a serine protease inhibitor that binds to and inhibits the activity of factors Xa and IIa, thereby preventing the formation of thrombin and fibrin.

Source

Biochemistry textbooks
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Hard MEDICAL Confidence: high