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: Surgery
[{'content': 'The earliest manifestation of increased intracranial pressure following head injury is: \nSelect and explain. \nA. Ipsilateral pupillary dilatation, B. Contralateral pupillary dilatation, C. Altered mental status, D. Hemiparesis', 'role': 'user'}, {'content': "Answer: C \nExplanation: Early signs of elevated iCP include drowsiness and a diminished level of consciousness (altered mental status). Coma and unilateral papillary changes are late signs and require immediate intervention. Ref: Harrison's Internal Medicine, 16th Edition, Page 1633; Clinical Hepatology: Principles and Practice of Hepatobiliary Diseases By Henryk Dancygier, Scott L. (FRW) Friedman, H. D. (CON) Allescher, U. (CON) Beuers, Volume 2, 2010, Page 938", 'role': 'assistant'}]