Which anatomical structure is located between the nasal fossae?

The nasal septum is the correct answer because it is the structure that divides the nasal cavity into two nasal fossae, which are the left and right chambers of the nasal passages. The nasal septum is made up of both cartilage and bone, specifically the perpendicular plate of the ethmoid bone and the vomer bone. This anatomical feature plays a critical role in supporting the structure of the nose, and it also assists in the regulation of airflow and the function of olfaction.

In contrast to the nasal septum, the other options refer to different anatomical structures that are not involved in delineating the nasal fossae. The mental foramen is an opening in the mandible that allows for the passage of nerves and blood vessels, far removed from the nasal cavity. The hamular process is a bony projection from the sphenoid bone, and while it contributes to certain aspects of facial structure, it is not situated between the nasal fossae. The zygomatic process, typically associated with the cheekbone, serves as a connection point for the zygomatic bone but is also unrelated to the nasal cavity division. Therefore, only the nasal septum is accurately described as the structure located between the nasal fossae.