What is the diagnosis of the patient described in the clinical case?

The patient has symptoms of anxiety and fear related to a traumatic event.
The patient has difficulty sleeping and concentrating.
The patient avoids situations related to the traumatic event.
The patient has recurrent nightmares related to the traumatic event.
a) Panic Disorder
b) Generalized Anxiety Disorder
c) Post-Traumatic Stress Disorder
d) Obsessive-Compulsive Disorder