Which one of the following proteins is involved in the coagulation of blood

The correct option is A Fibrinogen

Fibrinogen is soluble protein that is produced by the liver and found in blood plasma. It is one of the 13 coagulation factors responsible for normal blood clotting or coagulation of blood. When tissue damage results in bleeding, fibrinogen is converted at the wound into fibrin by the action of thrombin, a clotting enzyme.

So the correct answer will be option B.