Pacemaker regulating the rate of respiration ?
Ans. is 'd' i.e., Pre-Botzinger Complex "The main components of the respiratory control pattern generator responsible for automatic respiration are located in the medulla. Rhythmic respiration is initiated by a small group of synaptically coupled pacemaker cells in the pre-Botzinger complex on either side of the medulla between the nucleus ambiguus and the lateral reticular nucleus".
Pneumotaxic centre
Dorsal group of nucleus
Apneustic centre
Pre-Botzinger Complex