Recently, the Dopamine Hypothesis for Schizophrenia Has Been Challenged Because

Recently, the dopamine hypothesis for schizophrenia has been challenged because it has been discovered that:

A) effective new drugs suggest abnormal neurotransmitter activity of serotonin as well as dopamine.
B) excessive dopamine activity contributes to only some kinds of schizophrenia.
C) atypical antipsychotic drugs work exclusively on dopamine receptors.
D) those with catatonic schizophrenia respond better to atypical than to traditional antipsychotic drugs.