This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'The following is responsible for relaxation \nSelect and explain. \nA. Actin, B. SERCA, C. Both, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: SERCA is a calcium channel protein It causes relaxation by storing calcium Ref:Guyton and Hall textbook of medical physiology 12th edition,page number:86,87', 'role': 'assistant'}]