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': 'First investigation to be done in Hyphema is \nSelect and explain. \nA. Slit lamp examination, B. B scan, C. Tonometry, D. Funduscopy', 'role': 'user'}, {'content': 'Answer: C \nExplanation: First investigation to be done in Hyphema is Tonometry to detect raised Intraocular pressure.', 'role': 'assistant'}]