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': 'Receptor agonists possess: \nSelect and explain. \nA. Affinity but no intrinsic activity, B. Intrinsic activity but no affinity, C. Affinity and intrinsic activity with a + sign, D. Affinity and intrinsic activity with a - sign', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C. Affinity and intrinsic activity with a + signa. Agonist: Drug having affinity and intrinsic activity (IA)/efficacyb. Antagonist: Drug having affinity but no intrinsic activityc. Inverse agonist: Having affinity and intrinsic activity which is opposite to that of agonist e.g. beta carbolines at BDZ receptord. Partial agonist: Drug having affinity and intrinsic activity (IA)/efficacy less than agonist', 'role': 'assistant'}]