<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 77-year-old man with a history of hypertension and a 46 pack-year smoking history presents to the emergency department from an extended care facility with acute onset of headache, nausea, vomiting, and neck pain which started 6 hours ago and has persisted since. He is alert, but his baseline level of consciousness is slightly diminished per the nursing home staff. His temperature is 99.0F 37.2C, blood pressure is 16494 mmHg, pulse is 90min, respirations are 16min, and oxygen saturation is 98 on room air. The patients neurological exam is unremarkable with cranial nerves II-XII grossly intact and with stable gait with a walker. He is immediately sent for a head CT which is normal. What is the most appropriate next step in management?? A: Alteplase, B: Ibuprofen, acetaminophen, metoclopramide, and diphenhydramine, C: Lumbar puncture, D: MRI, E: Ultrasound,  <response>: This is a clinical vignette describing a 77-year-old man with a history of hypertension and smoking who presents with acute onset headache, nausea, vomiting, and neck pain. The description of the symptoms and their acute onset in an older patient raises suspicion for a subarachnoid hemorrhage. The initial head CT was normal, but a normal CT does not rule out a subarachnoid hemorrhage, especially if done soon after symptom onset. The next step would be an LP to analyze the cerebrospinal fluid for signs of bleeding. MRI could also be considered but LP is more sensitive in the first 6-12 hours after a bleed. Alteplase would not be indicated as there are no signs of an ischemic stroke. The other answer choices are symptomatic management but do not address finding the underlying cause.C: Lumbar puncture 