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': 'Lesion in which of the following pa of visual pathway result in homonymous hemianopia? \nSelect and explain. \nA. Chiasma, B. Optic tract, C. Optic nerve, D. Occipital lobe', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Homonymous hemianopia can be congenital, but is usually caused by brain injury such as from stroke, trauma, tumors, infection, or following surgery. Vascular and neoplastic lesions from the optic tract, to visual coex can cause a contralateral homonymous hemianopia. Injury to the right side of the brain will affect the left visual fields of each eye. The more posterior the cerebral lesion, the more symmetric (congruous) the homonymous hemianopsia will be.', 'role': 'assistant'}]