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
In a patient presenting with headache and eye complaints, Examination of right eye reveals: Right eye superotemporal quadrantanopia. Left eye reveals: Left eye superotemporal quadrantanopia, Left eye centrocecal scotoma. Likely site of lesion is - 
Select and explain. 
A. Left optic nerve + chiasma, B. Left optic tract + chiasma, C. Right optic nerve + chiasma, D. Right optic tract + chiasma
A: Left optic nerve + chiasma
Answer: A: Left optic nerve + chiasma 
Explanation: The patient has :-


Right superotemporal quadrantanopia
Left superotemporal quadrantanopia
Left centrocecal scotoma → Left optic nerve involvement e.g. toxic opic neuropathy


It has also been explained that early central chiasmatic lesion due to pituitary adenoma can cause upper temporal quadrantanopia.
So, best answer here is 'a' i.e. left optic nerve with optic chiasma.