Which Two of the Following Substantive Procedures Provide Evidence Over

Which two of the following substantive procedures provide evidence over the existence of trade receivables?
(1) Agreeing a sample of goods despatched notes to sales invoices and to the sales ledger
(2) Undertaking a receivables circularisation
(3) Review of post year-end cash receipts. If these relate to year-end receivables follow through to the sales ledger
(4) Recalculating the allowance for uncollectible accounts

A) 1 and 3
B) 2 and 4
C) 2 and 3
D) 1 and 4