Which of the following proteins plays a crucial role in regulating the coagulation cascade by inhibiting factor XIa and factor XIIa?

A C1-inhibitor ✓
B Antithrombin III
C Protein C
D Protein S

Explanation

C1-inhibitor is a protein that regulates the coagulation cascade by inhibiting factor XIa and factor XIIa, thereby preventing excessive clot formation.

Source

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