A soldier returned 3 months ago from a combat zone and was diagnosed with post-traumatic stress disorders (PTSD). Which social event would be most disturbing for this soldier?

A. Singing carols is calm, unlikely to trigger combat-related flashbacks. B. A seashore outing is generally peaceful and not typically a PTSD trigger. C. Fireworks mimic gunfire and explosions, which can easily trigger flashbacks, hypervigilance, and distress in combat veterans with PTSD. D. Halloween can be stimulating, but not as direct a combat reminder as fireworks.