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
Only intact eye movement in one and a half syndrome is 
Select and explain. 
A. Adduction of Ipsilateral eye, B. Abduction of Ipsilateral eye, C. Adduction of contralateral eye, D. Abduction of contralateral eye
D: Abduction of contralateral eye
Answer: D: Abduction of contralateral eye 
Explanation: Only abduction of contralateral eye is possible.