This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2017, Subject name: Pediatrics
A child presented with Microcephaly, Hepatomegaly and periventricular calcification. Best site from where specimen should be obtained for diagnosis of CMV by PCR? 
Select and explain. 
A. Urine, B. Blood, C. Liver biopsy, D. CSF
A: Urine
Answer: A: Urine 
Explanation: Congenital CMV infection C/F - Microcephaly Intracranial periventricular calcifications Chorioretinitis SNHL The diagnosis of congenital CMV infection is best confirmed by isolation of the virus from urine.