Which statement about the cricoid ring is true?

• A. Extends 360 degrees around the trachea and is the top ring.
• B. Extends around the esophagus.
• C. Is the only complete ring around the trachea.
• D. Forms the inferior border of the larynx.

Answer: (C)

The key fact is that the cricoid ring is the only complete ring around the trachea. The trachea itself has C-shaped cartilaginous rings that are open at the back, but the cricoid cartilage forms a full circle encircling the trachea and sits just below the larynx. This placement also means it forms the inferior border of the larynx, providing a sturdy connection between the larynx and trachea. The statement about encircling the esophagus is inaccurate because the esophagus lies posterior to the trachea and is not surrounded by a complete ring. The inferior-border aspect is true, but the defining feature tested here is being the only complete ring around the trachea.