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
Drug of choice for acyclovir resistant HHV is? 
Select and explain. 
A. Foscarnet, B. Cidofovir, C. Valacyclovir, D. Famciclovir
A: Foscarnet
Answer: A: Foscarnet 
Explanation: ANSWER: (A) FoscarnetREF: Harrisons 17th ed chapter 172Therapy with the antiviral drug foscarnet is useful in acyclovir-resistant cases.