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: Pharmacology
[{'content': "All of the following statements about clonidine are true EXCEPT: \nSelect and explain. \nA. It is an α–adrenergic agonist, B. It can cause dry mouth as an adverse effect, C. Prazosin completely antagonizes it's action, D. It inhibits sympathetic outflow.", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]