You are answering a USMLE-style medical question. Question: A 45-year-old man presents to his primary care provider for two weeks of low-grade fever and sore throat. Upon further questioning, the patient is found to have unprotected sex with both men and women with 3-5 partners per month. On workup, he is found to have an HIV viral load of 15,000 copies/mL with a CD4+ of 170 cells/mm^3. He is started on medical therapy. What should be included in his medication regimen? Options: A) Azithromycin B) Fluconazole C) Folinic acid D) Tetrahydrofolic acid Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.