b$.$ The auditors are concerned about transactions that have been recorded in the journals $($and subsequently in the ledgers$)$ that are not valid$$that is$,$ a transaction is recorded, but it did not actually occur $($e$.$g$.,$ a fraudulent overstatement of sales$).$ Which procedure would be most effective?

Multiple Choice

$(1)$ Trace from source documents to journals.

$(2)$ Vouch from journals to source documents.

Either $(1)$ or $(2).$