Pinky bauer, chief financial officer of harrison haulers, inc., suspects irregularities in the payroll system. she knows that 2,500 payroll vouchers have been issued since january 1, 2000, and her staff doesn't have time to inspect each voucher. so, she randomly selects 53 as a starting point and orders her staff to inspect the 53rd voucher and each voucher at an increment of 100 (53, 153, 253, her sample is a a. stratified sample b. simple random sample c. convenience sample d. systematic sample