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: Dental
Which of the following cannot be assessed with cephalometric radiograph? 
Select and explain. 
A. Mandibular retrusion, B. Vertical facial disproportion, C. Incisor position & anguLation, D. Adequacy of dental arch perimeter
D: Adequacy of dental arch perimeter
Answer: D: Adequacy of dental arch perimeter 
Explanation: None