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: Medicine
Purple toe syndrome is associated with which of the following drugs? 
Select and explain. 
A. Warfarin, B. Phenytoin, C. Theophylline, D. Thalidomide
A: Warfarin
Answer: A: Warfarin 
Explanation: None