Stratified random sampling is a method of selecting a sample in which

A、thesampleisfirstdividedintostrata,andthenrandomsamplesaretakenfromeachstratumNoneofthesealternativesiscorrect.;
B、variousstrataareselectedfromthesample;
C、thepopulationisfirstdividedintostrata,andthenrandomsamplesaredrawnfromeachstratum;
D、Noneofthesealternativesiscorrect.