<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 50-year-old man presents to the emergency department with a severe headache. The patient reports that it started approx. 2 hours ago and has steadily worsened. He describes it as a stabbing pain localized behind his left eye. The patient reports that he has been having similar headaches several times a day for the past week, most often at night. He denies any nausea, vomiting, and visual or auditory disturbances. He has no significant past medical history. Current medications are a multivitamin and caffeine pills. The patient reports regular daily alcohol use but does not smoke. His temperature is 37.0C 98.6F, the blood pressure is 12070 mm Hg, the pulse is 85min, the respiratory rate is 18min, and the oxygen saturation is 99 on room air. The patient is in moderate distress from the pain. The physical exam is significant for unilateral diaphoresis on the left forehead, left-sided rhinorrhea, and pronounced lacrimation of the left eye. The remainder of the physical exam is normal. Laboratory tests are normal. Non-contrast CT of the head shows no evidence of intracranial masses or hemorrhage. High flow oxygen and fluid resuscitation are initiated. Ibuprofen 200 mg orally is administered. Despite these interventions, the patient continues to be in significant pain. What is the next best step in management?? A: Verapamil, B: CT angiography, C: Administer subcutaneous sumatriptan, D: RF ablation of the left trigeminal nerve, E: Deep brain stimulation of the posterior inferior hypothalamus,  <response>: This appears to be a clinical vignette describing a patient with a severe, unilateral headache localized behind the left eye associated with autonomic symptoms such as lacrimation and rhinorrhea. The history, physical exam findings, and initial workup are consistent with a diagnosis of cluster headache. The next best step in management would be an abortive therapy to treat the acute attack. Sumatriptan is a first-line abortive therapy for cluster headaches that can be given subcutaneously for rapid relief. Verapamil is a preventive medication, not abortive. CT angiography may be indicated if considering alternate diagnoses but is not the next best step. Invasive procedures like RF ablation and deep brain stimulation are reserved for refractory cases.C: Administer subcutaneous sumatriptan 