For the past 3 days, a 25-year-old man known to be infected with HIV has had increasing fever, cough, and dyspnea, which has culminated in acute respiratory failure. On admission to the hospital, his temperature is 37.8°C. On physical examination, there are no significant findings. He undergoes a bronchoalveolar lavage that yields Pneumocystis jiroveci by direct fluorescent antigen testing. Within 1 week after initiation of therapy, he develops "target lesions" composed of red macules with a pale, vesicular center. The 2- to 5-cm lesions are distributed symmetrically over the upper arms and chest. Which of the following drugs is most likely to be implicated in the development of these lesions?
□ (A) Ritonavir
□ (B) Pentamidine
□ (C) Sulfamethoxazole
□ (D) Zidovudine
□ (E) Dapsone
□ (F) Adefovir
□ (G) Nevirapine
