Final answer:
The hypoxic drive to breathe in COPD patients is signaled by low levels of oxygen in the blood, not by increased levels of carbon dioxide as in healthy individuals. In COPD patients, reliance on the hypoxic drive can complicate oxygen therapy and requires careful monitoring.
Step-by-step explanation:
The hypoxic drive to breathe in COPD patients is a backup system that prompts breathing primarily due to low levels of oxygen rather than the normal stimulus in healthy individuals, which is high levels of carbon dioxide in the blood. In COPD, this hypoxic drive becomes a significant stimulus for breathing because the response to carbon dioxide levels can be blunted. So, for the question presented, the correct answer is d. Low levels of oxygen.
Hypoxia, resulting from low partial pressure of oxygen in arterial blood, can increase the drive to breathe in an attempt to raise oxygen levels. However, this can be problematic in COPD patients who have adapted to higher levels of carbon dioxide, and giving them too much supplemental oxygen can diminish their respiratory drive and lead to life-threatening situations.