Advice columnist Ann Landers once asked her readers with children to answer the following question: “If you had it to do over again, would you have children?” Readers were invited to send a response to this question by mail. Of the approximately 10,000 responses Landers received, approximately 70% said “no.” The sample:

AIs probably not representative because more than 10,000 people responded.

BHas little bias because more than 10,000 people responded, yielding a very large sample

CIs probably representative of all parents

DIs probably not representative of all parents because people who feel very strongly about this issue are more likely to respond than people who do not.