This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Medicine
[{'content': 'Drug of choice for acyclovir resistant HHV is? \nSelect and explain. \nA. Foscarnet, B. Cidofovir, C. Valacyclovir, D. Famciclovir', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ANSWER: (A) FoscarnetREF: Harrisons 17th ed chapter 172Therapy with the antiviral drug foscarnet is useful in acyclovir-resistant cases.', 'role': 'assistant'}]