A is correct: Audit (Premium) supports custom audit log retention policies. However, retention beyond one year requires the 10-year audit log retention add-on license per user. With this add-on, organizations can configure retention for 3, 5, 7, or 10 years to meet regulatory requirements. Reference: https://learn.microsoft.com/en-us/purview/audit-log-retention-policies
B is incorrect: Manual CSV exports are error-prone, difficult to search, and do not provide the integrity, tamper-resistance, or searchability required for regulatory compliance. Microsoft Purview audit retention policies provide a managed, compliant solution. Reference: https://learn.microsoft.com/en-us/purview/audit-log-retention-policies
C is incorrect: Audit (Premium) included with E5 retains Exchange, SharePoint, OneDrive, and Entra ID audit records for one year by default and 180 days for other activities. Seven-year retention requires the 10-year audit log retention add-on license. Reference: https://learn.microsoft.com/en-us/purview/audit-premium
D is incorrect: Audit (Standard) retains audit logs for only 180 days by default, not seven years. It does not support custom retention policies or extended retention periods required for long-term regulatory compliance in financial services. Reference: https://learn.microsoft.com/en-us/purview/audit-solutions-overview