A Graduate Student Is Learning to Use the DSM-IV-TR, and Is

A graduate student is learning to use the DSM-IV-TR, and is overwhelmed by all of the information. When he comes to the subtypes of schizophrenia, he learns that the subtypes are organized in a hierarchy. What does this tell the student?

A) Each subtype has one symptom that distinguishes it from the others.
B) The subtypes are based on the number of symptoms a patient exhibits.
C) The highest subtype in the hierarchy for which symptoms are present is the only one diagnosed, even if symptoms of lower subtypes are also present.
D) The subtypes are listed in order of their severity, and patients often progress up and down the list.