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: Ophthalmology
Treatment of nasolacrimal duct obstruction: 
Select and explain. 
A. Syringing, B. Probing, C. DCR, D. All
D: All
Answer: D: All 
Explanation: A. i.e. Syrignging B. i.e. Probing C. i.e. DCR, D. i.e. Dacryocystectomy