Answer: a, c, Solid organ transplant patients are prone to develop viral infection by virtue of exogenous immunosuppression. The most common post-transplantation viral infections are those caused by herpes viruses (CMV, herpes simplex virus [HSV], Epstein-Barr virus [EBV], and Varicella-Zoster virus [VZV]). All are most common during periods of maximal host immunosuppression that occur immediately post-transplantation and during periods of allograft rejection. CMV is a common cause of fever after solid organ transplantation, and evidence of CMV infection occurs in approximately 30% of patients. The most common presentation for CMV infection is that of a febrile, leukopenic patient with a cough, diffuse interstitial infiltrates on chest x-ray, and hypoxia. HSV infection causes primarily oral pharyngeal ulcerations in most cases, although sporadic cases of disseminated disease have been reported. EBV causes an occasional case of mononucleosis-type syndrome but has also been clearly indicated in the pathogenesis of post-transplantation lymphomas. VZV infection can present as disseminated and occasionally life-threatening infections in the nonimmune transplant patient or as painful herpes zoster in patients who have previously developed chicken pox