8. Which of the following statements about calibration is (are) correct?(AB) Calibration deternmines the relationship between the analyical response and the analyte concentration.(AC) Calibration does not inctude adjustment. i.c.. With calibration there is no technical intervention at the measuringinstrument.(AD) The chemical standards used in calibration can only be prepared from purified reagents.(AE) Gravimetric methods do not rely on calibration with chemical standards.(BC) Titration is a type of comparison methods.(BD) The least-squares method has two assumptions: (i) A linear relationship exists between the measured response y and thestandard analyte concentration x. (i) Erors exist in x values (concentrations) of the data points.