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': 'What is epiphora: September 2010 \nSelect and explain. \nA. Eveed upper eyelid following surgery, B. CSF running through nose after injury, C. Abnormal flow of tears due to obstructed lacrimal duct, D. CSF running through ears after injury', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Abnormal flow of tears due to obstructed lacrimal duct Epiphora is overflow of tears onto the face. A clinical sign or condition that constitutes insufficient tear film drainage from the eyes in that tears will drain down the face rather than through the nasolacrimal system', 'role': 'assistant'}]