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: Unknown
[{'content': 'Aldosterone synthesis is stimulated by which of the following: \nSelect and explain. \nA. ACTH, B. Hyperkalemia, C. Hypernatremia, D. Exogenous steroids', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref. Guyton. 13th edition. Page. 969', 'role': 'assistant'}]