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: Medicine
A 33 year old male presented with homonymous hemianopia. He also has ataxia and personality changes. Characteristic inclusions are seen in oligodendrocytes. What is the MOST probable diagnosis in this patient? 
Select and explain. 
A. Progressive multifocal leukoencephalopathy, B. Cruetzfeld-Jacob disease, C. Japanese encephalitis, D. Poliomyelitis
A: Progressive multifocal leukoencephalopathy
Answer: A: Progressive multifocal leukoencephalopathy 
Explanation: Progressive multifocal leukoencephalopathy(PML) is characterized pathologically by multifocal areas of demyelination of varying size distributed throughout the brain but sparing the spinal cord and optic nerves. Characteristic microscopic feature: 1. Oligodendrocytes have enlarged, densely staining nuclei that contain viral inclusions formed by crystalline arrays of JC virus (JCV) paicles. 2. Astrocytes are enlarged and contain hyperchromatic, deformed, and bizarre nuclei and frequent mitotic figures. Clinical presentation: Visual deficits (45%), typically a homonymous hemianopia Mental impairment (38%) (dementia, confusion, personality change) Weakness, including hemi- or monoparesis Ataxia Ref: Roos K.L., Tyler K.L. (2012). Chapter 381. Meningitis, Encephalitis, Brain Abscess, and Empyema. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.