A 30-year-old female undergoes a routine surgical procedure under general anesthesia. During the procedure, the anesthesiologist notices that the patient's tidal volume decreases and her respiratory rate slows down. Upon awakening, the patient complains of chest discomfort and difficulty breathing. Examination reveals decreased breath sounds on auscultation. Which of the following mechanisms best explains the respiratory changes observed during anesthesia and upon awakening?
A. Dysfunction of the medullary respiratory centers
B. Stimulation of the pneumotaxic center
C. Inhibition of peripheral chemoreceptors
D. Activation of central chemoreceptors
E. Activation of the Hering-Breuer reflex