A 28-year-old woman presents with a 6-month history of intermittent blurry vision and progressive numbness of the left leg. Vital signs: BP 118/76, HR 82, RR 16, Temp 37°C, SpO2 98%. Brain MRI reveals multiple periventricular white matter lesions with T2/FLAIR hyperintensities meeting Barkhof criteria, demonstrating dissemination in space and time. CSF analysis shows oligoclonal bands. No fever or recent systemic infection is reported. Which of the following is the most likely diagnosis?

1. A)Myasthenia gravis
2. B)Guillain-Barre syndrome
3. C)Multiple sclerosisGABARITO
4. D)Amyotrophic lateral sclerosis
5. E)Progressive multifocal leukoencephalopathy