The statement that provides evidence to support the classification of viruses as nonliving is:
"Viruses must infect living host cells in order to reproduce."
This characteristic distinguishes viruses from living organisms, which can reproduce independently. Other statements, while they describe aspects of viruses, do not serve as evidence for their nonliving classification. For example, the ability to mutate or the presence of genetic material do not inherently indicate whether an organism is living or nonliving.