Mutations appear more often in RNA viruses than in DNA viruses. Which property drives that difference?

1. RNA viruses carry only RNA as their genetic material and must copy it inside the host cell. 2. The polymerase enzymes they use are more likely to make copying errors than DNA polymerases are. 3. Those copying errors are mutations, so mutations occur more frequently in RNA viruses than in DNA viruses. 4. The practical result is that RNA viruses change and adapt to their host more rapidly. 5. Viral genomes are small rather than long, so genome length cannot be the reason. 6. Extra host repair of viral RNA would lower the mutation rate, not raise it, so that option inverts the logic. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 21 "Viruses", section 21.1 Viral Evolution, Morphology, and Classification_