This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': 'Longest acting oral sulphonamide is \nSelect and explain. \nA. Sulphadoxine, B. Sulphadiazine, C. Sulphacetamide, D. Mafenide', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Sulphadoxine is the longest acting orally absorbable drug. Mafenide is a topical drug.sulphadiazine and sulfacetamide are sho-acting oral drugsRef: KD Tripathi 6th ed .pg: 684', 'role': 'assistant'}]