Answer:
Correct Answer is Viruses
Step-by-step explanation:
Viruses are non-cellular entities that consist of a nucleic acid nucleus (DNA or RNA) surrounded by a protein layer. Although viruses are classified as bacteria, they are not considered living organisms. The microbes such as viruses cannot reproduce outside a host cell and cannot metabolize on their own. Viruses often infest prokaryotic and eukaryotic cells that cause disease.