This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hypeension, Arrhythmias, Dyslipidemia, Subject name: Pharmacology
[{'content': 'The only drug whose over dosage is not characterized by both hypotension and bradycardia is: \nSelect and explain. \nA. Propanolol, B. Verapamil, C. Clonidine, D. Theophylline', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Theophylline results in reflex tachycardia due to its vasodilatory action. Propanolol, verapamil and clonidine cause hypotension as well as bradycardia.', 'role': 'assistant'}]