Answer:
The correct answer will be- DNA acts as the genetic material of the phage
Step-by-step explanation:
A bacteriophage is a virus which infects the bacteria by inserting its genetic material into the host cell and using its DNA replication machinery to replicate or divide.
In the given question, when DNA was radiolabeled, radioactive DNA was observed in the host cell but when the protein was radiolabeled, it was not observed in the host cell as the molecule to be inserted in the host cell is the DNA (genetic material) to be replicated.
Thus, DNA acts as the genetic material of the phage is the correct answer.