How does a virus infect a host cell? A. It lays its lipids on a host cell. B. It lays its proteins on a host cell. C. It injects its nucleic acids into a host cell. D. It injects its carbohydrates into a host cell. How does a virus infect a host cell? A. It lays its lipids on a host cell. B. It lays its proteins on a host cell. C. It injects its nucleic acids into a host cell. D. It injects its carbohydrates into a host cell.