Which of the following statements regarding this design is not true?

A simple random sample was selected of large urban school districts throughout New England. The selected districts were identified as target districts. Within each district, a simple random sample of its high schools was chosen and the principals of those high schools were interviewed.

A. The is an example of a multi-stage cluster sample.
B. Results from the interviews cannot be used to infer responses of the population of interest.
C. The population of interest is the set of all high school principals in New England.
D. Not every subset of principals has the same chance of selection.
E. All of these statements are true.