Which of the following options about big data is correct?( )

A、Theacquireddatarequiresacleanandaccuratestate.;
B、Theemergenceofbigdataapplicationhasitsspecialsocialneeds.;
C、Intheeraofbigdata,theexhaustivemethodisregardedasanunreliablemethod.;
D、Thesampleddatacanbeobtainedinsteadofthewholedata.