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
The earliest manifestations of increased intracranial pressure following head injury is : 
Select and explain. 
A. Ipsilateral papillary dilatation, B. Contralateral papillary dilatation, C. Altered mental status, D. Hemiparesis
C: Altered mental status
Answer: C: Altered mental status 
Explanation: Answer is C (Altered mental status) : `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.' -Harrisons