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
Longest acting oral sulphonamide is 
Select and explain. 
A. Sulphadoxine, B. Sulphadiazine, C. Sulphacetamide, D. Mafenide
A: Sulphadoxine
Answer: A: Sulphadoxine 
Explanation: 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