question: Q:A 29-year-old woman is brought to the emergency department after an episode of syncope. For the past 10 days, she has had dyspnea and palpitations occurring with mild exertion. The patient returned from a hiking trip in Upstate New York 5 weeks ago. Except for an episode of flu with fever and chills a month ago, she has no history of serious illness. Her temperature is 37.3°C (99.1°F), pulse is 45/min, respirations are 21/min, and blood pressure is 148/72 mm Hg. A resting ECG is shown. Two-step serological testing confirms the diagnosis. Which of the following is the most appropriate treatment?? 
  {'A': 'Intravenous ceftriaxone', 'B': 'Beta blocker', 'C': 'Oral doxycycline', 'D': 'Atropine', 'E': 'Permanent pacemaker implantation'},