The Young Children's Charity of Eastern Canada Would Like an Accurate

The Young Children's Charity of Eastern Canada would like an accurate estimate of how much it costs to raise a child between the ages of 2 and 12 each year for its fundraising campaign.The organization hired you to find out how much households spent on raising a child in 2011.The charity gave you a list of four million residential telephone customers in the area.You sampled every four-thousandth address on the list.You survey each sampled household by telephone. In this study,each address of a telephone customer is your

A) sampling frame.
B) observation unit.
C) sampling element.
D) sampling unit.
E) sampling interval.