The correct option is C nasal septum
The nasal septum divides the nasal cavity into two halves.
The initial portion of the nasal cavity is called the nasal vestibule.
The passageway between the septum and the turbinates is called meatus. It is connected to the upper part of the pharynx called the nasopharynx.
Nasal turbinates or nasal conchae are curled bones that hold the meatus open.