Cluster sampling and stratified sampling are similar in that for both of them: A. the target population is first divided into several subpopulations B. all subpopulations will be chosen C. the elements within subpopulations are homogeneous D. the elements across subpopulations are heterogeneous A questionnaire returned from the field may be unacceptable for several reasons. Which of the reasons below is NOT one of those reasons? A. Parts of the questionnaire may be incomplete. B. The returned questionnaire is physically incomplete. For example, some pages are missed. C. Someone who does not qualify for participation answers the questionnaire. D. The questionnaire does not uplift, motivate, or encourage the respondent to become involved