Final answer:
Hypoventilation causing carbon dioxide retention stimulates central chemoreceptors, which respond by increasing respiration to maintain homeostasis.
Step-by-step explanation:
Hypoventilation that results in the retention of carbon dioxide will primarily stimulate the central chemoreceptors. These receptors are located in the brain and brainstem and are sensitive to changes in the concentration of carbon dioxide and hydrogen ions. Increased levels of carbon dioxide lead to increased levels of hydrogen ions, decreasing the pH of the blood. The activity of the central chemoreceptors prompts the respiratory centers to increase the rate and depth of respiration, allowing more carbon dioxide to be expelled and thus maintaining a normal homeostatic state.