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
[{'content': 'Decreased effect of warfarin is seen in case of : \nSelect and explain. \nA. Nephrotic syndrome, B. Acute intake of alcohol, C. Concurrent treatment with phenylbutazone, D. Congestive heart failure', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]