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: Biochemistry
Which of the following conditions most rapidly produce functional deficiency of vitamin k 
Select and explain. 
A. Premature delivery of the baby, B. Pure vegan diet, C. Broad spectrum antibiotics consumption, D. Warfarin therapy
D: Warfarin therapy
Answer: D: Warfarin therapy 
Explanation: Warfarin prevents the recycling of vitamin K by blocking the activity of Vitamin K epoxide reductase, thus creating a functional vitamin K deficiency.