Which of the following is a symptom of PTSD in adults?

Replaying the experience repeatedly is a recognized symptom of PTSD (Post-Traumatic Stress Disorder) in adults. This symptom is often referred to as intrusive memories or flashbacks, where individuals relive the traumatic event as if it were happening again. This can cause significant distress and can interfere with a person's ability to function in daily life.

In contrast, finding joy in everyday activities indicates a level of emotional stability and engagement with life, which is not characteristic of PTSD. A constant sense of safety and increased trust in others also suggest a positive outlook and mental well-being, which are often undermined in individuals suffering from PTSD. These conditions typically involve heightened anxiety, mistrust, and avoidance behaviors, which are fundamentally at odds with the feelings represented by the other choices.