Final answer:
The septal cartilage forms part of the nasal septum. It is the anterior portion, and it is what you can touch with your fingers. So, the correct answer is a. Septal cartilage.
Step-by-step explanation:
The nasal septum is a wall composed of bone and cartilage that separates the left and right nasal cavities. The components of the nasal septum include the septal cartilage, the perpendicular plate of the ethmoid bone, and the vomer bone. The septal cartilage forms the anterior portion of the septum and is flexible. The perpendicular plate of the ethmoid bone and the vomer bone form the posterior part of the septum. The question asks which listed structure is part of the nasal septum. Answer: a. Septal cartilage is part of the nasal septum.
In contrast, the nasal conchae are separate structures that extend into the nasal cavity and are not part of the nasal septum. The nasal conchae include the superior, middle, and inferior nasal conchae. They help to warm, moisturize, and clean the air as it enters the nose but do not contribute to the structure of the nasal septum.