Which of the following statements are wrong about transform domain analysis of discrete time signals？

A、Transformdomainanalysisofdiscrete-timesignalsisacommonmethodofdiscrete-timesignalprocessing.;
B、Transformdomainanalysisofdiscretetimesignalsistheonlymeansofdiscretetimesignalanalysis.;
C、Transformdomainofdiscrete-timesignalanalysisisanecessarymethodfordiscrete-timesignalanalysis.;
D、Transformdomainanalysisofdiscretetimesignalsisadispensablemeansofdiscretetimesignalanalysis.