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
A young man with blurring of vision in right eye, followed by left eye after 3 months, showing disc hyperemia, edema, circumpapillary telangiectasia with normal pupillary response with centrocecal scotoma on perimetry, the cause is: 
Select and explain. 
A. Typical optic neuritis, B. Acute Papilledema, C. Toxic optic neuropathy, D. Leber's hereditary optic neuropathy
D: Leber's hereditary optic neuropathy
Answer: D: Leber's hereditary optic neuropathy 
Explanation: D. i.e. Leber's hereditary optic neuropathy