<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 28-year-old woman with a history of migraines presents to your office due to sudden loss of vision in her left eye and difficulty speaking. Two weeks ago she experienced muscle aches, fever, and cough. Her muscle aches are improving but she continues to have a cough. She also feels as though she has been more tired than usual. She had a similar episode of vision loss 2 years ago and had an MRI at that time. She has a family history of migraines and takes propranolol daily. On swinging light test there is decreased constriction of the left pupil relative to the right pupil. You repeat the MRI and note enhancing lesions in the left optic nerve. Which of the following is used to prevent progression of this condition?? A: Dexamethasone, B: Methotrexate, C: Natalizumab, D: Infliximab, E: Adalimumab,  <response>: This is a clinical case scenario describing a 28-year-old woman with a history of migraines who is presenting with new symptoms of sudden vision loss in one eye and difficulty speaking. She also has a recent history of fever, cough, and muscle aches. Important background includes a similar episode of vision loss 2 years ago, family history of migraines, and daily propranolol use. On exam she has a pupil defect suggesting optic nerve involvement. Repeat MRI shows enhancing lesions in the left optic nerve concerning for demyelination. Based on the clinical presentation, exam findings, and imaging, this patient likely has multiple sclerosis with an acute exacerbationrelapse causing optic neuritis. The question asks which medication is used to prevent disease progression in multiple sclerosis. The choices provided are various immunosuppressants and biologics used in autoimmune conditions.C: Natalizumab 