Since this question asks you to detect the RNA genome of hepatitis A, you need a technique which can access that genome. RT-PCR converts RNA into DNA, which is easier to detect. Alternatively, and perhaps more usefully, hybridization of probes for hepatitis A genetic sequences might also detect the genome of this virus.
Work Step by Step
To get this answer, scan through the chapter and look for techniques which can be used to detect RNA-- any of these have potential to be answers for this question.