Drug of choice for panic disorders is -
Drug of choice for panic disorder is antidepressants. SSRIs are preferred antidepressants over tricyclic antidepressants.
However, imipramine is the only antidepressant amongst the given options.
You should also keep in mind that initially benzodiazepine is used early in the course for immediate relief of panic symptoms

Therefore,

Drug of choice for panic disorders → Antidepressants (SSRIs)
Drug of choice of acute panic attack → Benzodiazepines
Nitrazepam
Imipramine
Diazepam
Clonidine