It's HY and there are some basic rules (with few exceptions).
For example, Herpes viruses are ds DNA viruses and enveloped viruses are more fragile and cannot survive the bile in GUT.
Therefore, enveloped viruses tend to infect the respiratory tract and non-enveloped the GI tract.
Other than that you have to memorize the unique characteristics of HY viruses i.e. HIV, Hepatitis, Parvovirus, Papillomavirus etc.