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 morphological type of cataract is most visually handicapping ? \nSelect and explain. \nA. Cortical, B. Nuclear, C. Posterior subcapsular, D. Zonular', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Cupuliform (Posterior subcapsular) cataract lies right in the pathway of the axial rays and thus causes an early loss of visual acuity.', 'role': 'assistant'}]