Recognise the figure and find out the correct matching
A. a-viral RNA ,b-RNA polymerase ,c-viral DNA ,d-viral RNA
B. a-viral RNA ,b-reverse transcriptase ,c-viral RNA ,d-viral DNA
C. a-viral DNA ,b-DNA polymerase,c-viral DNA ,d-viral RNA
D. a-viral DNA ,b-reverse transcriptase,c-viral DNA,d-viral RNA