Final answer:
Post-Traumatic Stress Disorder (PTSD) is the anxiety-related disorder that would best apply to Randy's situation.
Step-by-step explanation:
The best anxiety-related disorder that would apply to Randy's situation is Post-Traumatic Stress Disorder (PTSD). PTSD is an anxiety disorder that develops after a person experiences a severe psychological trauma, such as physical or sexual abuse. The symptoms of PTSD include intrusive memories, nightmares, hypervigilance, and avoidance of triggers related to the trauma.