During the most recent year's audit of Hoover Enterprises, senior management has advised the auditors that a new and more effective system of internal control has been designed and implemented by external consultants and the internal audit function. As a result of this information, what approach might the auditing firm take with respect to internal control? The external auditors will be required to obtain written assurances from senior management, documenting the effectiveness of the new system of internal control, for inclusion in the audit file. The auditor is likely to proceed with testing of the new controls, and if the new system is determined to be robust and effective, the auditor will issue a qualified opinion on internal control. The auditor may presume that their previous understanding of internal control is no longer valid, and will likely amend audit procedures to document the effectiveness of the new system. The external auditors will focus the audit time and resources on solely testing the client's system of internal control. No substantive testing will be performed