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: Microbiology
Herpes - zoster is caused by : 
Select and explain. 
A. Herpes-simplex type I, B. Herpes-simplex type II, C. Epstein-barr virus, D. Varicella
D: Varicella
Answer: D: Varicella 
Explanation: “Herpes zoster is reactivation of latent chicken pox virus (varicella zoster virus) from the dorsal root ganglia.”
Characteristic features of Herpes zoster

Unilateral vesicular eruption within a dermatome often associated with severe pain. The dermatome from T3 to L3 are most frequently involved.
Ramsay hunt syndrome : Rare form of herpes zoster affecting the facial nerve with eruption on tympanic membrane and external auditary canal with ipsilateral facial palsy.
Most debiliating complication of herpes zoster in both the normal and immunocompromised host is pain