This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
Which of these structures appears radiopaque? 
Select and explain. 
A. Maxillary sinus, B. Nasal fossa, C. Nasal septum, D. Mental foramen
C: Nasal septum
Answer: C: Nasal septum 
Explanation: Radiopaque refers to that portion of the radiograph that appears light or white. Radiopaque structures are dense and absorb or resist the passage of the X-ray beam, E.g., Enamel, dentin and bone.
Nasal septum
On the panoramic radiograph, it appears as a vertical radiopaque partition that divides the nasal cavity.
Reference: Freny R Karjodkar Oral Radiology Principles and Interpretation 2nd  edition page no 251