This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pharmacology
Which one of the following drugs is associated with the development of a lupus-like syndrome, especially in patients identified as "slow acetylators"? 
Select and explain. 
A. Arniodarone, B. Clonidine, C. Nitroglycerin, D. Procainamide
D: Procainamide
Answer: D: Procainamide 
Explanation: Procainamide is metabolized by N-acetyltransferase (a phase II drug metabolism reaction) to form N-acetyl-procainamide (NAPA), which itself has antiarrhythmic activity. Patients who are classified as slow acetylators may develop SLE-like symptoms when treated with procainamide. Other drugs metabolized via N-acetyltransferase, including isoniazid and hydralazine, have also been associated with lupus-like symptoms in slow acetylators.