This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
Vitamin K is involved in the action of the following proteins except 
Select and explain. 
A. Factor II, B. Factor X, C. Factor I, D. Protein C
C: Factor I
Answer: C: Factor I 
Explanation: Vitamin K dependent factors are Factors II, VII, IX, X, Protein C and S Ref: Ganong 25th ed/page 566