<prompt> A patient has a congenital deficiency in factor XIII fibrin-stabilizing factor. What would analysis of his blood reveal?Prolonged prothrombin timeProlonged whole blood clotting timeProlonged paial thromboplastin timeEasily breakable clot  <response>: Fibrin monomers polymerize to form a clot. Creation of a strong clot requires the presence of fibrin stabilizing factor that is released from platelets within the clot. The other clotting tests determine the activation of extrinsic and intrinsic pathways or number of platelets. 