Final answer:
Limiting access to master payroll records to supervisory personnel in the payroll department would best serve to prevent payroll clerk from increasing pay rate and sharing overpayments. So, the correct answer is option B.
Step-by-step explanation:
The best way to prevent an illegal act where a payroll clerk increases the hourly pay rate of employees and shares the resulting overpayments with them is option B, which is limiting access to master payroll records to supervisory personnel in the payroll department.
By restricting access to the master payroll records, it reduces the likelihood of unauthorized changes being made to the pay rates. This control measure helps ensure that only authorized personnel with proper oversight are able to make changes to employee pay records. So, the correct answer is option B.