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: Medicine
[{'content': 'A 40 years old female is came in the depament by describing "1 have worst headache of my life". The investigation of choice for this patient \nSelect and explain. \nA. Four vessels carotid angiography, B. Computed tomography (CT), C. MRI, D. No scan is required', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer- B. Computed tomography (CT)It is a case of "acute subarachnoid hemorrhage".The explosive onset of severe, excruciating headache is a common feature of subarachnoid haemonhage (SAH).Diagnosis of Subarachnoid hemorrhageThe hallmark of aneurysmal rupture is blood in the cerebrospinalfluid.More than 95% cases have enough blood to be visualized on a high quality non contract CT scan obtained within 72h.MRI can also be used to diagnose subarachnoid hemorrhage but CT is more sensitive than MRI for acute blood', 'role': 'assistant'}]