This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Rhinitis, Subject name: ENT
Most common cause of obstruction in atrophic rhinitis is: 
Select and explain. 
A. Excessive formation of crust, B. Polyp, C. Synechiae, D. Hypertrophy of turbinate
A: Excessive formation of crust
Answer: A: Excessive formation of crust 
Explanation: (a) Excessive formation of crust(Ref. Cummings, 6th ed., 695)The excessive crusting leads to nasal obstruction in spite of roomy cavities.On removal of crusts there is bleeding. But there is no synechiae formation. There is no polypoidal change .