A nurse is caring for a client who is admitted to a mental health facility after attempting suicide. Which of the following actions should the nurse take first?

The correct answer is B: Implement continuous one-to-one observation. This should be done first to ensure the client's safety and prevent any further suicide attempts. Continuous observation allows the nurse to closely monitor the client for any signs of distress or suicidal ideation. It provides immediate intervention if needed and ensures the client is not left alone, reducing the risk of harm. Asking the client to sign a no-suicide contract (A) is important but should come after ensuring immediate safety. Establishing rapport (C) and encouraging group therapy (D) are important for long-term care but not the priority in this critical situation.