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: Ophthalmology
The common cause of bilateral internuclear ophthalmoplegia is: 
Select and explain. 
A. Multiple sclerosis, B. Lead toxicity, C. Diphtheria, D. Diabetes mellitus
A: Multiple sclerosis
Answer: A: Multiple sclerosis 
Explanation: Ans. Multiple sclerosis