Nelson, a Schizophrenic Patient, Has Just Begun Taking Antipsychotic Medication

Nelson, a schizophrenic patient, has just begun taking antipsychotic medication. He took his first dose about 12 hours ago, but so far his family sees no change in his condition. What advice should they be given? ​

A) If he doesn't show improvement in another 12 hours, a different kind of medication should be tried.
B) Patients usually don't begin responding to antipsychotic drugs for at least a few days.
C) He may have been misdiagnosed as schizophrenic.
D) Early changes due to antipsychotic medication are usually not apparent to nonprofessionals, who are unfamiliar with the signs of improvement.