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': 'Which is the thinnest pa of the lens of eye? \nSelect and explain. \nA. Anterior pole, B. Posterior pole, C. Posterior capsule, D. Apex', 'role': 'user'}, {'content': "Answer: B \nExplanation: The lens is thinnest at the posterior pole. The crystalline lens is surrounded by a lens capsule. Lens capsule is a thin transparent elastic membrane secreted by the lens epithelial cells largely composed of type IV collagen. The capsule is 11- 15microm thick at the anterior pole. The posterior capsule thickness decreases to a minimum at the posterior pole to about 4microm. Ref: Adler's Physiology of the Eye: Expe Consult by Leonard A Levin, Page 47", 'role': 'assistant'}]