This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lens, Subject name: Ophthalmology
[{'content': 'The crystalline lens derives its nourishment from - \nSelect and explain. \nA. Blood vessels, B. Connective tissue, C. Aqueous and vitreous, D. Zonules', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The crystalline lens, being avascular structure is dependent for its metabolism on chemical exchanges with the aqueous humour. Some nutrition is also derived from the vitreous humour, but it is much less than that derived from aqueous humour.', 'role': 'assistant'}]