Final answer:
D. Clear irritants from the airways. Sneezing and coughing both help to clear irritants from the airways by expelling air forcefully and removing mucus and debris.
Step-by-step explanation:
Sneezing and coughing both attempt to clear irritants from the airways. When sneezing, nerves lining the nasal passage are irritated, resulting in a forceful expulsion of air from the mouth, which helps remove mucus and debris from the respiratory tract. Similarly, coughing is a response to irritated nerves lining the airways, causing the expulsion of air from the trachea to clear mucus and debris from the upper respiratory tract.