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: ENT
For deviated nasal septum, surgery is required for -a) Septal spur with epistaxisb) Marked septal deviationc) Persistent rhinorrhead) Recurrent sinusitise) Prolonged DNS 
Select and explain. 
A. abc, B. acd, C. bcd, D. abcd
D: abcd
Answer: D: abcd 
Explanation: Indications for surgery

Persistent unilateral nasal obstruction and recurrent headache.
Deviation causing recurrent sinusitis or otitis media
Recurrent epistaxis from septal spur.
Access for operation in polypectomy with DNS.
As a part of septorhinoplasty for cosmetic correction of external nasal deformities.
As a approach to hypophysectomy