A nurse is caring for a client with posttraumatic stress disorder (PTSD). Which manifestation is the nurse most likely to observe?

A. Hypersomnia (excessive sleeping) is more commonly associated with depression, not PTSD. B. "Increase" is incomplete and unclear, making it an invalid option. C. Flashbacks or intrusive memories are hallmark symptoms of PTSD, where the individual relives the traumatic event through vivid memories or nightmares. D. Euphoric mood is not typical of PTSD; affected individuals often experience anxiety, irritability, hypervigilance, or emotional numbness.