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: Medicine
[{'content': "In Conn's disease, there is an excess of: \nSelect and explain. \nA. Adrenaline, B. Aldosterone, C. Cortisol, D. Noradrenaline", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]