Which of these job recruitment sites is not a job listing aggregator?

List the seven roles of people in a buying center

What will be an ideal response?

Which of the following statements about sample control is true?

A) Mailing lists for mail surveys are sometimes unavailable, outdated, or incomplete. B) It is possible to identify specific user groups within a mail panel and to direct the survey to households with specific characteristics. C) It can be difficult to prevent respondents from completing an Internet survey multiple times. D) All of the above statements are true.