The correct answers are: The performance of a confirmation of accounts receivable; Reviewing the allowance for irrecoverable debts for reasonableness; Performing analytical procedures on the ageing of trade receivables.

The performance of a confirmation of accounts receivable may help show up non-existent receivables or receivables who may not pay. Reviewing the allowance for irrecoverable debts and performing analytical procedures on the ageing of receivables also both help ensure that receivables are not overstated.

Taking a sample of sales orders and checking them through the system helps ensure that receivables are complete, it does not provide evidence as to overstatement. Checking the authorisation of credit notes is a test of controls.