One Disadvantage of Early Descriptions of Schiziophrenia,such as Kraepelin's Use

One disadvantage of early descriptions of schiziophrenia,such as Kraepelin's use of the term "dementia praecox," is that

A) they assumed that what we call schizophrenia only occurred in elderly patients.
B) they were actually describing Alzheimer's dementia,not schizophrenia.
C) they did not distinguish between the varying types of schizophrenia that we know about today.
D) they assumed the intellectual functioning of patients remained constant even as their bodies aged.