Walters Created a List of All Sales Invoices to Verify

Multiple Choice

  Walters created a list of all sales invoices to verify that they were supported by the appropriate shipping documents. Invoice number 15 was selected first for examination, followed by the invoices numbered 30, 45, 60, 75, 90, and so on until 40 invoices had been selected.

A) unrestricted random (UR)
B) systematic random (SR)
C) haphazard (H)
D) block (B)