Basophils and mast cells release heparin that prevents clotting and promotes blood flow. Thromboplastin is released by platelets at injured tissue that makes anti-heparin and initiates the clot formation. Fibrinogen is a soluble blood protein that becomes insoluble and forms fibrin strands during last steps of clotting. Albumins serve to maintain the osmotic concentration of blood. Thus, the correct answer is d.

──────────────────────────────────────────────────────────────────────────────────────────