A 55-year-old male is admitted to the hospital after a motor vehicle accident resulting in severe head trauma. He is intubated and mechanically ventilated due to impaired consciousness and respiratory drive. Despite adequate sedation and ventilatory support, he exhibits irregular breathing patterns characterized by prolonged inspiratory pauses followed by abrupt expirations. Which of the following brainstem centers is most likely affected in this patient, resulting in his abnormal breathing pattern?
A. Dorsal respiratory group (DRG)
B. Ventral respiratory group (VRG)
C. Pneumotaxic center
D. Apneustic center
E. Pre-Botzinger complex