Which audit procedure is most effective in testing credit sales for$$ overstatement?

$1.$

Trace a sample of postings from the sales journal to the sales account in the general ledger.

$2.$

Vouch a sample of recorded sales from the sales journal to shipping documents.

$3.$

Prepare an aging of accounts receivable.

$4.$

Trace a sample of initial sales orders to sales recorded in the sales journal.

Provide reason for answer, please.