Bacteriophage doesn't have a nucleus.
Option C.
Step-by-step explanation:
Bacteriophage is a virus that is present in our surroundings. Its a phage virus that attacks bacteria and killing it. Bacteriophage has a tadpole like structure with a polygonal head and a neck and 6 tails. The polygonal head is formed of carbohydrates, along with the neck and tails. The head has inside it DNA that is its nucleic acid and genetic material. It's not enclosed in any nucleus. It has some proteins inside the head too.
The phage virus attaches itself with bacteria and drills the bacterial cell wall by the neck and pushes the genetic material inside as a mode of infection.