Advice columnist Ann Landers once asked her readers with the children to answer the following question: "If you had it to do over again, would you've 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 is
A. the approximately 10,000 readers who wrote in.
B. the approximately 70% of women who answered "no."
C. the respondents that regretted having children.
D. all readers.