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: Pharmacology
Which of the following medications would be prescribed most frequently to patients suffering from chronic atrial fibrillation ? 
Select and explain. 
A. Lidocaine, B. Bretylium, C. Warfarin, D. Adenosine
C: Warfarin
Answer: C: Warfarin 
Explanation: None