Which openings are referred to as the nostrils within the vestibular zone?

• A. Anterior Nares
• B. Posterior Nares
• C. Nasopharynx
• D. Oropharynx

Answer: (A)

Nostrils are the anterior nares—the external openings at the entrance of the nasal cavity, right at the nasal vestibule. The vestibular zone is the shallow area just inside these openings. The posterior nares are the internal openings (choanae) leading to the nasopharynx, while the nasopharynx and oropharynx are parts of the throat behind the nasal and oral cavities, not the nostrils themselves. So the nostrils in the vestibular zone are the anterior nares.