Explanation:
To ensure that a disaster recovery test is successful, it is most important to determine whether all critical business functions were successfully recovered and duplicated. Although ensuring that only materials taken from offsite storage are used in the test is important, this is not as critical in determining a test’s success. While full recovery of the processing infrastructure is a key recovery milestone, it does not ensure the success of a test. Achieving the RTOs is another important milestone, but does not necessarily prove that the critical business functions can be conducted, due to interdependencies with other applications and key elements such as data, staff, manual processes, materials and accessories, etc.