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': 'Which of the following effects of adrenaline would be blocked by phentolamine but NOT by propranolol ? \nSelect and explain. \nA. Cardiac stimulation, B. Relaxation of bronchial smooth muscle, C. Relaxation of the uterus, D. Contraction of the radial smooth muscle in the iris', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]