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
Retrobulbar injection of xylocaine blocks all of the following except: 
Select and explain. 
A. 3rd cranial nerve, B. 4th cranial nerve, C. 6th cranial nerve, D. Ciliary nerves and ciliary ganglion
B: 4th cranial nerve
Answer: B: 4th cranial nerve 
Explanation: Ans. 4th cranial nerve