Which of the Following Statements Is True Concerning Classification Systems

Which of the following statements is true concerning classification systems for mental disorders?

A) It is far more important that they be reliable than it is for them to be valid.
B) Classification systems make it more difficult to gather statistics on the incidence and prevalence of disorders.
C) Classification systems meet the needs of medical insurance companies who need diagnoses in order to authorize payment of claims.
D) Although they assist scientists who are researching disorders, they always inhibit our ability to communicate about abnormal behavior in a consistent way.