Ziyad Received a Questionnaire in the Mail Asking About His

Ziyad received a questionnaire in the mail asking about his general buying habits. He was asked to identify the specific products that he typically buys, and the amount of each product that he typically uses. If Ziyad completes the questionnaire and returns it, he will have taken part in research that incorporates

A) the survey method.
B) naturalistic observation.
C) a case study approach.
D) archival research.