This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory System, Subject name: Physiology
Pacemaker regulating the rate of respiration- 
Select and explain. 
A. Pneumotaxic centre, B. Dorsal group of nucleus, C. Apneustic centre, D. Pre-Botzinger complex
D: Pre-Botzinger complex
Answer: D: Pre-Botzinger complex 
Explanation: Ans. (d) Pre-Botzinger complex(Ref: Ganong, 25th ed/p.655)Pre-Botzinger Complex - "The pacemakers of respiration"Initiates the respiratory rhythmThis complex contains six group of neurons that functions as "central pattern generator" for initiation of respirationLocated in the ventrolateral medullaRhythmically drives the discharge of phrenic motor neurons that innervate diaphragm