18. An auditor wishes to sample 200 sales receipts from a population of 5, 000 receipts issued during the last year . The receipts have preprinted serial numbers and are arranged in chronological ( and thus serial number ) order . The auditor randomly chooses a receipt from the first 25 receipts and then selects every 25 th receipt thereafter . The sampling procedure described here is called A. Systematic random sampling B. Monetary - unit sampling C. Judgment interval sampling* D. Variables sampling*