A Research Study on the Quality of Customer Service of Telecom

Multiple Choice

A research study on the quality of customer service of telecom call centers, chose 20 call centers for the study, with the condition that at least four had to be from Pakistan, two had to be selected from Ireland, and, another four were to be from the Philippines. What type of sampling method was used by this study?

A) stratified
B) cluster
C) quota
D) convenience