What is the primary role of platelet factor 4 in blood coagulation?

A Promoting platelet aggregation
B Inhibiting heparin activity ✓
C Enhancing fibrinolysis
D Regulating thrombin generation

Explanation

Platelet factor 4 is a protein that inhibits heparin activity, which is essential for regulating blood coagulation.

Source

Guyton and Hall Textbook of Medical Physiology
Hematology Hematology: Blood Components Hematology: Blood Components Medium MEDICAL Confidence: high