Ever since she was mugged a month ago, Mona experiences acute anxiety when she leaves her apartment. Her doctor writes a prescription for a drug to temporarily reduce her anxiety, but he tells Mona that she may need to see a therapist because taking this type of drug over a long period is not the treatment of choice. What type of drug was most likely prescribed by Mona's doctor?

A) an antipsychotic
B) lithium carbonate
C) a tranquilizer
D) an antidepressant