This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: External Nose, Subject name: ENT
Angle between nasal septum and lower border of upper lateral cailage is ____ 
Select and explain. 
A. 40 0, B. 60 0, C. 500, D. 15 0
D: 15 0
Answer: D: 15 0 
Explanation: - Angle between the nasal septum and lower border of upper lateral cailage is generally > 10-15deg The internal nasal valve, in normal development, is thenarrowest poion of the nasal cavity and is bounded bythe septum medially, caudal edge of the upper lateral cailage and head of the inferior turbinate laterally and nasalfloor inferiorly. The apex of the internalnasal valve is approximately 10-15 degrees in Caucasiansand wider in non-Caucasian populations.