While studying in a noisy cafeteria, you get sleepy and doze off for a few minutes.
You awaken with a start and realize that all the cafeteria sounds have just "come back." While you were dozing, this auditory input was blocked from reaching your auditory cortex by
a. the temporal lobe.
b. the hypothalamus.
c. the reticular activating system.
d. the medulla oblongata.
e. the vestibulocochlear nerve.