This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
[{'content': 'Earliest feature in Multiple sclerosis is \nSelect and explain. \nA. Optic neuritis, B. Inter nuclear ophthalmologia, C. Ataxia, D. Weakness', 'role': 'user'}, {'content': 'Answer: A \nExplanation: * Initial Symptoms and percent of cases Sensory loss -37% Optic neuritis- 36% Weakness -35% Ataxia-11%. Optic nerve Pain and temporary vision loss in one eye are common symptoms of optic neuritis. Optic neuritis is linked to multiple sclerosis (MS), a disease that causes inflammation and damage to nerves in your brain and spinal cord Ref Davidson edition23rd pg1110', 'role': 'assistant'}]