Final answer:
The nucleic acid of the bacteriophage enters through the host cell wall, leaving the capsid outside. Only the nucleic acid and potentially some replication enzymes enter the cell, not the entire virus or the capsid alone.
Step-by-step explanation:
What part of the attached bacteriophage enters through the host cell wall? The answer is c) The nucleic acid. Unlike animal viruses, the nucleic acid of bacteriophages is injected into the host cell leaving the capsid outside. The bacterial cell's own polymerase then begins translating viral mRNA into protein that can assemble into new virions or participate in the lytic process. Viral enzymes may also be introduced to assist in breaking down the bacterial cell wall for the release of progeny viruses. Therefore, only the nucleic acid and possibly some enzymes necessary for replication enter the bacterial cell, not the entire virus nor the capsid alone.