This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pharmacology, Subject name: Pharmacology
[{'content': 'Marketing of these drugs is difficult and they are highly expensive to produce: \nSelect and explain. \nA. Orphan drugs, B. Rare drugs, C. Over the counter drugs, D. Emergency drugs', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Orphan Drugs are drugs or biological products for diagnosis/treatment/ prevention of a rare disease or condition. cost of developing and marketing is high eg: sodium nitrite, fomepizole, liposomal amphotericin B, rifabutin, succimer, somatropin, digoxin immune Fab (digoxin antibody), liothyronine (T3), etc Over the counter, (OTC)drugs or Nonprescription drugs can be sold even by grocery stores-they are available and can be dispensed without prescription Ref ;KD Tripathi pharmacology 7 th edition (page no; 5)', 'role': 'assistant'}]