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
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: 
Select and explain. 
A. Paial 3rd nerve palsy, B. Internuclear ophthalmoplegia, C. Duane's reactionary syndrome, D. Absence of medial rectus muscle
B: Internuclear ophthalmoplegia
Answer: B: Internuclear ophthalmoplegia 
Explanation: Ans. Internuclear ophthalmoplegia