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
Aspirin is contraindicated in a case who is on treatment with: 
Select and explain. 
A. Prednisolone, B. Warfarin, C. Theophyline, D. Oral contraceptives
B: Warfarin
Answer: B: Warfarin 
Explanation: Warfarin