This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Which antibiotic decreases absorption of iron ? \nSelect and explain. \nA. Sulfonamide, B. Tetracyclines, C. Erythromycin, D. Ciprofloxacin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e., Tetracycline Factors facilitating iron absorption - Acid, ascorbic acid (Vit C), amino acids containing SH radical, meat. All these are reducing substances which enhance conversion of Fe" to Fe" and thus improve absorption. Factors impending iron absorption - antacids, alkalies, phosphate (rich in egg yolk), phytates (in maize, wheat), tetracyclines, presence of other food in stomach.', 'role': 'assistant'}]