This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney Stones & Renal Tubular Acidosis, Subject name: Medicine
[{'content': 'All are indicated in a 30-year-old patient with increased serum cystine and multiple renal stones except: \nSelect and explain. \nA. Cysteamine, B. Increase fluid intake, C. Alkalinization of urine, D. Penicillamine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The clinical diagnosis of profile given in the question is CYSTINURIA . Cystinuria- AR,defect in re-absorptive transpo of cystine and the dibasic amino acids ornithine, arginine, and lysine from the luminal fluid of the renal proximal tubule and small intestine. Urinalysis- hexagonal shaped crystals: pathognomonic of cystinuria. The foundation of cystine stone prevention is adequate hydration and urinary alkalinization. When this conservative therapy fails, the addition of drugs, such as D-penicillamine and captopril. -The clinical profile should not be confused with Cystinosis which is treated with Cysteamine.', 'role': 'assistant'}]