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 nerve which is most frequently involved in herpes zoster ophthalmicus is: 
Select and explain. 
A. Frontal nerve, B. Nasociliary nerve, C. Lacrimal nerve, D. Facial nerve
A: Frontal nerve
Answer: A: Frontal nerve 
Explanation: Ans. Frontal nerve