This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacodynamics, Subject name: Pharmacology
[{'content': 'Shelf life of a drug is:- \nSelect and explain. \nA. Time from manufacturing date to expiry date, B. The time after which the drug loses its potency, C. Time in which 93% of drug is eliminated, D. The time after which drug become toxic', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Shelf life: It is the time for which drug can be sold by the pharmacist. It is calculated as time between expiry date and manufacturing date.', 'role': 'assistant'}]