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 used for exocytosis \nSelect and explain. \nA. Calcium, B. Sodium, C. Potassium, D. All', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Calcium plays an impoant role in exocytosis Exocytosis is an active vesicular transpo system', 'role': 'assistant'}]