When accounts receivable are confirmed at an interim date, auditors need not be concerned with
a. Obtaining a summary of receivables transactions from the interim date to the year- end date.
b. Obtaining a year- end trial balance of receivables, comparing it to the interim trial balance, and obtaining evidence and explanations for large variations.
c. Sending negative confirmations to all customers as of the year- end date.
d. Considering the necessity for some additional confirmations as of the balance sheet date if balances have increased materially.