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: ENT
A 60-year old male presents with painful, 141 oupet. vesicles over erythematous plaques in T3 dermatome region of trunk. Which of the following would be the most likely causative organism? 
Select and explain. 
A. Varicella zoster, B. Herpes simplex, C. Pox virus, D. Papilloma virus
A: Varicella zoster
Answer: A: Varicella zoster 
Explanation: Ans. a. Varicella zosterA 60-year-old male presents with painful, grouped vesicles over erythematous plaques in T dermatome region of trunk. Varicella zoster is the most likely causative organism.