A school board wishes to determine opinions of parents regarding the assigning of homework in mathematics classes. Which of the following procedures would be most appropriate for obtaining a statistically unbiased sample?

A. Survey a selection of parents from the official school roster of parents.

B. Survey a selection of people whose names are randomly chosen from the telephone directory.

C. Survey people chosen from the first 1,000 names on an alphabetical listing of parents of mathematics students.

D. Survey a selection of people whose names are randomly chosen from a listing of parents of mathematics students.