Answer the following question given this paragraph: 

A virus cannot reproduce on its own. However, a virus can reproduce by infecting the cell of a living host. Inside the host cell, the virus uses the cell’s structures, materials, and energy to make copies of itself.


Q: What can reproduce by infecting the cell of a living host?

 Choices:

- bacteria

- mucus

- carcinogens

- virus

A:
virus
