The best method to prevent wire transfer fraud by bank employees is system-enforced dual control. System-enforced dual control is a segregation of duties control that requires two or more individuals to perform or authorize a transaction or activity using a system that enforces this requirement. System-enforced dual control can prevent wire transfer fraud by requiring independent verification and approval of payment requests, amounts, and recipients by different bank employees using a system that does not allow any single employee to complete the transaction alone. The other options are not as effective as system-enforced dual control in preventing wire transfer fraud, as they do not involve independent checks or approvals using a system. Independent reconciliation is a detective control that can help compare and confirm payment records with bank statements, but it does not prevent wire transfer fraud from occurring. Re-keying of wire dollar amounts is an input control that can help detect any errors or discrepancies in payment amounts, but it does not prevent wire transfer fraud from occurring. Two-factor authentication control is an access control that can help verify the identity and authorization of bank employees, but it does not prevent wire transfer fraud from occurring. References: CISA Review Manual (DigitalVersion), Chapter 3, Section 3.2