<prompt> The relationship between sulphonamide and PABA isMetabolic antagonismSynergismIntermediate compound formationChelation  <response>: Sulfonamides have structural similarity with PABA .therefore, they competitively inhibit the enzyme responsible for the incorporation of PABA into dihydropteroic acid, the immediate precursor of folic acidRef: DM Vasudevan, 7th edition, page no: 491, 61 