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
[{'content': 'A 60 year old man presented with watering from his left eye since 1 year. Syringing revealed a patent drainage system. Rest of the ocular examination was normal. A provisional diagnosis of lacrimal pump failure was made. Confirmations of the diagnosis would be by- \nSelect and explain. \nA. Dacryoscintigraphy, B. Dacryocystography, C. Pressure syringing, D. Canaliculus irrigation test', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Following tests are available for evaluation of epiphora:\n\nFor mechanical obstruction:-\n\tRegurgitation test, fluorescein dye test, lacrimal syringing test, Jones dye test, dacryocystography.\nFor functional (physiological) obstruction due to lacrimal pump failure:-\n\tDacryoscintigraphy or radionucleotide dacryocystography (more sensitive), Fluorescein dye disappearance test.', 'role': 'assistant'}]