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: Physiology
[{'content': 'The function of Phospholamban is \nSelect and explain. \nA. Regulates Na+ K+ pump, B. Transports calcium out of the mitrochondria, C. Binds actin with myosin, D. Inhibits Ca++ pump on sarcoplasmic reticulum', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Phospholamban inhibits calcium pump on sarcoplasmic reticulum, thereby preventing uptake of Ca++ from the sarcoplasm. \nWhen it is phosphorylated, the Ca++ channels open up and uptake of Ca++ is increased into the sarcoplasmic reticulum.', 'role': 'assistant'}]