This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Antiplatelets and Fibrinolytics, Subject name: Pharmacology
A young male patient presented with prolonged bleeding time. You take a detailed history and ask the patient for intake of NSAIDs as these can prolong the bleeding time. The patient refuses the intake of any form of NSAIDs. No other drug history was obtained. All of the following drugs can prolong bleeding time except 
Select and explain. 
A. Cephalosporins, B. Multivitamins containing Vitamin K, C. Methylxanthines, D. Anti-depressants
B: Multivitamins containing Vitamin K
Answer: B: Multivitamins containing Vitamin K 
Explanation: Ans. (B) Multivitamins containing Vitamin K(Ref: Goodman and Gilman 12/e p1806)Vitamin K is involved in activation of clotting factors II, VII, IX and X. It thus, decreases the risk of bleeding.