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': 'Agonist is having: \nSelect and explain. \nA. Affinity with intrinsic activity is 1, B. Affinity with intrinsic activity is 0, C. Affinity with intrinsic activity is –1, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]