Kat needs comprehensive and accurate information about several psychological disorders for her research. why is the diagnostic and statistical manual of mental disorders (dsm-iv-tr) a good reference for kat's research? a. this manual contains careful descriptions of the symptoms of different disorders. b. this manual provides a deep understanding of the causes and treatments of different psychological disorders. c. this manual people with psychological disorders treat themselves. d. this manual is a combination of theories and myths about different psychological disorders.