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
Vitamin K: 
Select and explain. 
A. Helps in formation of prothrombin, B. Inhibition of antithrombin, C. Prevention of capillary fragility, D. Stimulation of hematopoiesis in red bone marrow
A: Helps in formation of prothrombin
Answer: A: Helps in formation of prothrombin 
Explanation: None