This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea and sclera, Subject name: Ophthalmology
[{'content': 'Corneal endothelium was seen by \nSelect and explain. \nA. Pachymeter, B. Keratometer, C. Tonometer, D. Slit lamp bio-microscope', 'role': 'user'}, {'content': 'Answer: D \nExplanation: (Refer: AK Khurana Comprehensive Ophthalmology, 6th edition, pg no. 95 - 96)Corneal endothelium:It consists of single layer of polygonal (mainly hexagonal cells)They are visualized by slit lamp bio-microscope and appear like a mosaicThe cell density is 30000 cells/mm2 in young adults and decreases with ageThese cells contain active pump mechanism', 'role': 'assistant'}]