Final answer:
Adjustment disorder is considered the least severe stress-related disorder, characterized by difficulty coping with stress but with less severe symptoms compared to PTSD or acute stress disorder.
Step-by-step explanation:
The question relates to the severity of stress-related disorders. Out of the options provided, adjustment disorder is often considered the least severe stress-related disorder. Adjustment disorder is a response to a significant life change or stressor, characterized by emotional and behavioral symptoms that are disproportionate to the event, but neither as intense nor as prolonged as those in post-traumatic stress disorder (PTSD) or acute stress disorder. While PTSD is a severe anxiety disorder that occurs after exposure to extreme trauma, and acute stress disorder is a short-term condition that develops after a traumatic event, adjustment disorder involves difficulty in coping with stressors. It's often less debilitating than PTSD, which can involve long-term symptoms such as intrusive and painful memories, jumpiness, negative emotional states, and avoidance of reminders of the traumatic event.