Final answer:
The most appropriate response is to show empathy and provide reassurance.
Step-by-step explanation:
The most appropriate response for the nurse in this situation would be to show empathy and provide reassurance to the client. The nurse should acknowledge the client's feelings and validate their concerns. For example, the nurse could say, "I understand that you may be feeling scared right now. It's natural to have these thoughts, but I assure you that we are here to provide the best care for you. Can you tell me what specifically is making you feel this way so that we can address it together?"