What should be introduced in the section of method in social science research ? ( )

A、How a study is conducted
B、The demographic information of study objects (such as, sample size, age, gender, educational and socio-economic background )
C、Study procedures of collecting and analyzing data to generate findings.
D、Through data and justification, this section of method enables the reader to evaluate the reliability and validity of the study. And it also makes it possible for other researchers to replicate the study.