In each of the following situations, indicate whether Walters, CPA is using unrestricted random (UR), systematic random (SR), haphazard (H), or block (B) selection.?

A. 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.

?B. To test the occurrence assertion regarding sales invoices, Walters randomly selected invoices from the database storage disk for examination.

?C. To ensure proper authorization of payroll functions, Walters selected all transactions during the last 5 days of each pay period to be included in the sample.

?D. Sales invoices are commonly stored in a filing cabinet during the 30-day return period before being input in the company's database. To ensure the 30-day return period was not exceeded, Walters decided to pull a few invoices from each drawer until the desired sample size was collected for examination.

?E. T&T Company's purchase orders are already pre-numbered and listed in numerical order within the company's database. As a result, Walters was able to use one of the firm's computer programs to identify random numbers and match each number with a corresponding purchase order to test the accuracy assertion.

?F. Using a random number table, Walters identified a series of 50 numbers and located the corresponding employee identification number to select time cards for examination.

?G. Walters used a computer listing of T&T's credit memos, which totaled 2,400 items, to select 4 random starting points for examination. The remaining memos were identified for testing by selecting every 24th item until the sample size reached 100 memos.