A nurse is caring for a client who has posttraumatic stress disorder (PTSD) after being physically assaulted. The client is unable to recall any details of the event. Which of the following defense mechanisms should the nurse recognize that the client is displaying?

A reason: Dissociation. Dissociation involves a disconnection between thoughts, identity, consciousness, and memory. The inability to recall details of a traumatic event is a common dissociative response in PTSD, where the mind separates from the distressing experience. B reason: Rationalization. Rationalization involves creating a logical explanation to justify unacceptable feelings or behaviors. It does not involve memory loss or detachment from the event, making it an incorrect choice in this context. C reason: Undoing. Undoing is a defense mechanism where a person tries to reverse or undo feelings by doing something that indicates the opposite feeling. It does not involve forgetting or dissociating from traumatic events. D reason: Reaction formation. Reaction formation involves expressing the opposite behavior or emotion of what one truly feels. It does not involve memory loss or dissociation from the traumatic event, making it an incorrect choice in this context.