How often does the erectile tissue in the inferior concha swell to restrict airflow?

The correct answer reflects the physiological process known as the nasal cycle, which involves the alternating engorgement and decongestion of erectile tissue in the inferior concha. This cycle occurs approximately every 30 to 60 minutes, allowing one side of the nasal cavity to swell and restrict airflow while the other side remains open. This mechanism is believed to help maintain moisture and temperature in the air being inhaled and also assists in preventing the desiccation of the nasal mucosa.

In this context, while the other options suggest timeframes that could seem plausible, they do not align with the established understanding of the nasal cycle, which is specifically approximately every 30 to 60 minutes. Thus, the provided answer effectively encapsulates the regularity and purpose of this physiological response.