<prompt> Dicumarol is a drug that impairs the utilization of vitamin K by the liver. Dicumarol therapy, therefore, would decrease the plasma concentration of which of the following procoagulants?ProthrombinFibrinogenFactor XIAc-globulin factor V  <response>: Dicumarol inhibits the action of vitamin K, which is a necessary cofactor for the enzyme that catalyzes the conversion of glutamic acid residues to g-carboxyglutamic acid residues.Six of the proteins involved in clotting require conversion of a number of glutamic acid residues to g-carboxyglutamic acid residues before being released into the circulation, and hence all six are vitamin K-dependent. These proteins include factors II prothrombinOthers are; factors VII, IX, and X, protein C, and protein S Ref: Ganongs Review of Medical Physiology Twenty-Third Edition Page No: 535 