This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Anaesthesia
[{'content': 'All of the following decreases cerebral blood now, and intracninial pressure except: \nSelect and explain. \nA. Propofol, B. Thiopentone, C. Ketamine, D. Etomidate', 'role': 'user'}, {'content': 'Answer: C \nExplanation: (C) Ketamine', 'role': 'assistant'}]