In prioritizing control recommendations to prevent unauthorized changes to the payroll master file, the control having the greatest impact would be? 1) segregation of duties between the preparation of paychecks and their review 2) segregation of duties between the preparation of paychecks and their distribution 3) segregation of duties between the authorization of changes and the physical handling of paychecks 4) having the controller closely review and then approve any changes to the master file