Final answer:
The central chemoreceptors, responsible for monitoring changes in pH, CO₂, and oxygen levels in the blood, are located in the medulla oblongata.
Step-by-step explanation:
The central chemoreceptors are specialized receptors within the brain that are primarily responsible for monitoring the levels of carbon dioxide (CO₂), pH, and to a lesser extent, oxygen, in the blood and cerebrospinal fluid (CSF). These chemoreceptors contribute to the regulation of respiration by signaling the respiratory centers to adjust breathing rates when necessary. Specifically, the central chemoreceptors are located in the medulla oblongata, and they are distinct from the peripheral chemoreceptors found in the aortic bodies and carotid bodies. Therefore, the answer to the question 'Where are the central chemoreceptors located?' is C. Medulla oblongata.