This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of orbit, Lids and lacrimal apparatus, Subject name: Ophthalmology
Congenital dacrocystitis, the block is at- 
Select and explain. 
A. Lacrimal calnaliculi, B. Nasolacrimal duct, C. Punctum, D. None
B: Nasolacrimal duct
Answer: B: Nasolacrimal duct 
Explanation: Also known as dacryocystitis neonaturum. Due to congenital blockage in the nasolacrimal duct. Ref: ak khurana 6th edition REF IMG