This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'Vitamin K dependent clotting factors include the following, EXCEPT: \nSelect and explain. \nA. Factor VII, B. Factor VIII, C. Prothrombin, D. Factor IX', 'role': 'user'}, {'content': "Answer: B \nExplanation: Factors II (prothrombin), VII, IX, and X require vitamin K for their synthesis. Vitamin K is required for the posttranslational carboxylation of glutamic acid, which is necessary for calcium binding to gamma-carboxylated proteins such as prothrombin (factor II); factors VII, IX, and X; protein C; protein S; and proteins found in bone (osteocalcin) and vascular smooth muscle (e.g., matrix Gla protein). Warfarin-type drugs inhibit gamma-carboxylation by preventing the conversion of vitamin K to its active hydroquinone form. Ref: Weitz J.I. (2011). Chapter 30. Blood Coagulation and Anticoagulant, Fibrinolytic, and Antiplatelet Drugs. In B.C. Knollmann (Ed), Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.", 'role': 'assistant'}]