The correct option is C Bacteriophages
Eukaryotic cells contain membrane bound organelles and includes a nucleus. Eukaryotes can be single celled or multicellular such as plants, fungi and monera etc. Bacteria are an example of prokaryotes. Prokaryotic cells do not contain a nucleus or any other membrane bound organelle. Viruses are neither prokaryotes nor eukaryotes because they lack the characteristics of living things except the ability to replicate which they accomplish only in living cells. Bacteriophages are viruses so they are neither prokaryotes nor eukaryotes. So the correct answer is 'bacteriophages'.