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
[{'content': "A patient presents with diplopia with limitation of adduction in the left eye and abducting saccade in the right eye.Convergence is preserved. Most likely etiology is: \nSelect and explain. \nA. Paial 3rd nerve palsy, B. Internuclear ophthalmoplegia, C. Duane's reactionary syndrome, D. Absence of medial rectus muscle", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Internuclear ophthalmoplegia', 'role': 'assistant'}]