Severing a cat's reticular formation from higher brain regions causes the cat to

A) become violently aggressive.
B) cower in fear.
C) experience convulsive seizures.
D) Lapse into a coma.

Severing the reticular formation from higher brain regions will result in the cat lapsing into a coma. The reticular formation plays an important role in regulating consciousness and arousal, so severing it from higher brain regions essentially disconnects the brain's arousal system from the rest of the brain. This will result in the cat losing consciousness and being unable to wake up.