This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
An adult hypeensive male presented with sudden onset severe headache and vomiting. On examination, there is marked neck rigidity and no focal neurological deficit was found. The symptoms are most likely d/t 
Select and explain. 
A. Intracerebral parenchymal hemorrhage, B. Ischemic stroke, C. Meningitis, D. Subarachnoid hemorrhage
D: Subarachnoid hemorrhage
Answer: D: Subarachnoid hemorrhage 
Explanation: Harrison's principles of internal medicine 17 th edition. *SAH characterised by headache ,which is generalised and sudden onset ,neckstiffness,vomiting is common *Althoughsudden headache without focal neurological deficit may occur as hallmark feature of aneurysmal rupure ,but focal neurological deficit may occur .