This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pharmacology
Which of the following is vitamin K dependent clotting factor 
Select and explain. 
A. Factor 7, B. Factor 1, C. Factor 11, D. Factor 12
A: Factor 7
Answer: A: Factor 7 
Explanation: Refer Gaming 21/e p 547 Vitamin K dependent factors are clotting factors 2 7 9 10 And anticlotting factors protein C and protein S