This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
[{'content': 'Which is the only drug effective in improving EDSS in multiple sclerosis? \nSelect and explain. \nA. Methotrexate, B. Fingolimod, C. Glatiramer acetate, D. Natalizumab', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The statement only drug effective in improving EDSS seems to be wrong because many drugs have shown to reduce disease severity on EDSS scores. Expanded disability status score(EDSS) is a scoring system for MS where high score means worsening neurological dysfunction. Maximum reduction in EDSS is seen in natalizumab group. Ref :Harrisons 18th ed.', 'role': 'assistant'}]