Which One of the Following Internal Accounting Control Procedures Is

Which one of the following internal accounting control procedures is effective in preventing duplicate payment of vendors' invoices?

A) Cancelled cheques should be sent to persons other than the cashier or accounting department personnel.
B) The invoices should be stamped, perforated or otherwise effectively cancelled before submission for approval of the voucher.
C) Properly authorised and approved vouchers with appropriate documentation should be the basis for cheque preparation.
D) Unused voucher forms should be prenumbered and accounted for.