A sAmplE oF A populAtion is oFtEn ExAminED For thE Following purposEs ExCEpt ______.
A．to mAkE A morE ACCurAtE prEDiCtion oF trEnD
B．to improvE EFFiCiEnCy AnD AvoiD unnECEssAry work
C．to sAvE thE trouBlE oF ApproAChing EvEry mEmBEr
D．to prEDiCt ChArACtEristiCs oF thE EntirE populAtion