QUESTION THREE [15] Your firm is the auditor of Bob Ltd, a large industrial company. In the management letter resulting from the previous year's audit, you raised a number of concerns with the directors relating to the company's salaries system. Your evaluation of the salaries application suggested to you that the controls over amendments to the employee master-file could be circumvented to make, for example, unauthorized changes to the salary grade of an employee. Required Describe the controls which should be in place to ensure that changes to salary grades on the employee mater-file are valid, accurate and complete