This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
[{'content': 'Length of intraorbital pa of the optic nerve is \nSelect and explain. \nA. 10-12 mm, B. 20-24 mm, C. 25-30 mm, D. 35-40 mm', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Length of optic nerve - 5 cm Intraocular poion - 20 mm Intraorbital poion - 30 mm', 'role': 'assistant'}]