Answer: D
Medulla
Explanation: The medulla oblongata is a cone shaped nerve cell mass in the hindbrain, it controls a number of involuntary functions like circulation and respiration. the medulla oblongata helps to regulate sneezing, swallowing, digestion, breathing and the functions of heart and blood vessels.
The medulla is the connection between the forebrain and the midbrain because sensory neurons and motor from the forebrain and the midbrain travel through the medulla.
Because the medulla regulates breathing and heart functions, its destrucction is definitely life threatening.