Which of the following statements about viruses is true?

Viruses are unique and fundamentally different from living organisms in how they reproduce. They lack the cellular machinery required to replicate on their own, which means they must invade a host cell in order to reproduce. Once inside a host cell, a virus can hijack the cell's machinery to produce new viral particles, effectively making the host cell a factory for replicating the virus. This characteristic of needing a host to reproduce is a defining feature of viruses and underscores their dependence on living organisms for propagation.

Options that suggest viruses can be killed by antibiotics, survive independently, or possess a complex cellular structure do not accurately describe their nature. Antibiotics are designed to target bacterial infections and have no effect on viruses. Viruses are not equipped to survive independently; they can only exist in a dormant state outside of host organisms and need to infect a host for reproduction. Lastly, viruses are not considered complex cellular entities; they lack cellular structure, containing only a simple composition of genetic material surrounded by a protein coat.