This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Physiology
[{'content': 'Activation of which receptor causes pulmonary vasoconstriction? \nSelect and explain. \nA. Alpha 2 adrenergic, B. H2 histamine, C. M3 cholinergic, D. ETA epithelial receptor', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Activation of ETA receptor causes pulmonary vasoconstriction. These are endothelin receptors.Ref: Ganong review of medical physiology, 23rd edition Page no: 609', 'role': 'assistant'}]