This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Integrated QBank, Subject name: Unknown
[{'content': 'A 40-year-old HIV positive male, presented with complaints of a characteristic rash over his back and buttocks. The rash was painful and has worsened over the past 3 days. Physical examination is unremarkable. Rest of the skin examination is normal. A smear was prepared from the lesions. All of the following drugs are approved for the above condition except: - \nSelect and explain. \nA. Acyclovir, B. Valcyclovir, C. Ganciclovir, D. Famciclovir', 'role': 'user'}, {'content': 'Answer: C \nExplanation: This is a case of Herpes zoster/ Shingles. The image shows hemorrhagic vesicles and pustules on an erythematous base in a dermatomal distribution. 2nd image shows a Tzanck smear with classical multinucleate giant cells seen in varicella. Drugs approved are: - Valcyclovir Famciclovir Acyclovir Ganciclovir is approved for CMV infection.', 'role': 'assistant'}]