How Common Are Delusions in Schizophrenia

How common are delusions in schizophrenia?

A) They are experienced by approximately 50 percent of schizophrenics.
B) Delusions are an essential feature of schizophrenia; the presence of delusions is required for a diagnosis of schizophrenia.
C) Over 90 percent of those with schizophrenia experience delusions.
D) While hallucinations are a common occurrence in schizophrenia, delusions are rare.