which one of the following drugs is a barbiturate?
['amobarbital (Amytal)', 'butabarbital (Butisol)', 'pentobarbital (Nembutal)', 'secobarbital (Seconal)', 'belladonna and phenobarbital (Donnatal)', 'butalbital/acetaminophen/caffeine (Esgic, Fioricet)', 'butalbital/aspirin/caffeine (Fiorinal Ascomp, Fortabs)']