Final answer:
The nurse should intervene if the assistant gives the client a pan of water for bathing herself with a radioactive implant. The staff wearing a dosimeter film badge when interacting with the client is appropriate.
Step-by-step explanation:
The nurse should intervene if option A is observed. Giving the client a pan of water to bathe herself while having a radioactive implant can be dangerous. The radioactive implant may contaminate the water and pose a risk for exposure to others. It is important to maintain safety precautions when dealing with radioactive materials. The staff wearing a dosimeter film badge when interacting with the client (option D) is appropriate as it helps monitor their radiation exposure.