Infectious agents that may infect the human body include viruses, bacteria, fungi, and parasites. Of these infectious agents, viruses are the only ones that are NOT part of the Cell Theory. Why?

A. Viruses reproduce rapidly once inside cells.

B. Viruses contain hereditary information.

C. Viruses can infect the cells of a variety of organisms.

D. Viruses are not composed of cells and are not considered living.