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': 'Which of the following propey of the drug will enable it to be used in low concentration? \nSelect and explain. \nA. High affinity, B. High specificity, C. Low specificity, D. High stability', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Affinity is the ability of the drug to bind with the receptor The receptor occupancy by the drug is needed to elicit a response, so drug with hyper affinity will occupy a larger number of receptor and produce more response at a given concentration than a drug with lower affinity. Ref: KD Tripathi 8th ed', 'role': 'assistant'}]