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': 'ED 50 is a measure of- \nSelect and explain. \nA. Toxicity, B. Safety, C. Potency, D. Efficacy', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Potency Median effective dose o The dose that will produce half the maximum (50%) response. o More the ED, is the potency.", 'role': 'assistant'}]