This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
An emerging viral pathogen causing pyelonephritis in kidney allografts is - 
Select and explain. 
A. Rotavirus, B. Herpes simplex, C. Polyomavirus, D. Influenza virus
C: Polyomavirus
Answer: C: Polyomavirus 
Explanation: Diseases caused by human polyomavirus infections are most common among immunocompromised people; disease associations include BK virus with nephropathy in renal transplant and non-renal solid organ transplant patients, JC virus with progressive multifocal leukoencephalopathy, and Merkel cell virus (MCV) Ref Davidson 23rd edition pg 877