MRI scans of schizophrenic patients have indicated that:

A. schizophrenic subjects have lower levels of catecholamines than nonschizophrenic subjects
B. schizophrenic subjects have higher levels of dopamine than nonschizophrenic subjects
C. schizophrenic subjects have higher levels of serotonin than nonschizphrenic subjects

D. schizophrenic subjects have larger ventricles than nonschizophrenic subjects