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 the client is displaying?

Choice A reason: Dissociation involves a disruption in memory, identity, or perception. In PTSD, dissociative amnesia is a protective mechanism that blocks traumatic memories. Choice B reason: Rationalization involves justifying behaviors or feelings with logical explanations, not memory loss. Choice C reason: Undoing is an attempt to reverse or negate unacceptable thoughts or actions, often through symbolic acts. Choice D reason: Reaction formation involves expressing the opposite of one’s true feelings, not memory suppression.