Final answer:
The nurse should advise the client to keep their provider's and therapist's number with them as part of the Safety Plan to prevent relapse.
Step-by-step explanation:
The appropriate statement by the nurse to assist a client with schizophrenia in developing a Safety Plan to prevent relapse would be option C: 'You should keep your provider's and your therapist's number with you.' This statement is appropriate because it emphasizes the importance of having access to healthcare professionals who can provide support and guidance in case of a relapse. Keeping the provider's and therapist's number handy ensures that the client can easily reach out for assistance when needed. It is crucial for individuals with schizophrenia to have a strong support system in place to proactively manage their condition and prevent relapses.