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: Physiology
Arousal response is mediated by 
Select and explain. 
A. Dorsal column, B. Reticular activating system, C. Spinothalamic tract, D. Vestibulo cerebellar tract
B: Reticular activating system
Answer: B: Reticular activating system 
Explanation: Arousal response in cerebral cortex is activated by stimulation of Reticular activating system.