Answer: c. dissociative fugue
Dissociative fugue has to do with people losing some or all of the memories of their past and losing awareness of their identity. They might even leave their family and job and flee from their usual environments.
It's not GAD because that has to do with persistent and excessive worry/anxiety about a lot of things. It's not insanity because that has to do with a person not being able to distinguish fantasy from reality. It's not schizophrenia because that has to do with a person slowly losing contact with reality and experiencing hallucinations, delusions, and bizarre behaviour.