<prompt> 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:Typical optic neuritisAcute PapilledemaToxic optic neuropathyLebers hereditary optic neuropathy  <response>: D. i.e. Lebers hereditary optic neuropathy 