Answer:
The answer is D. Viruses.
Step-by-step explanation:
Viruses are the smallest abiotic infectious agents. Viruses are considered nonliving, as they cannot reproduce or produce energy on their own. They must live inside a host cell. Viruses enter our cells and use them to reproduce and produce energy. Once a virus is finished with the host cell, the host cell is destroyed. Examples of viruses are HIV, West Nile, and Zika.