正解:A
As outlined in the Microsoft Identity and Access Administrator (SC-300) Official Study Guide and Microsoft Learn - Monitor and Analyze Sign-ins in Azure AD , the Azure AD Sign-ins log retains sign-in events for a limited duration depending on the tenant's licensing tier.
For the default Azure AD Free , Office 365 , and Azure AD Premium P1/P2 tiers, the standard retention period for sign-in logs is 14 days . This means that administrators can query, review, or export sign-in data only for sign-ins that occurred within the past 14 days using the Azure portal , Microsoft Graph API , or Azure AD PowerShell .
The document ation specifies:
"Azure AD stores audit and sign-in events for up to 14 days in the Azure portal. For longer retention, you must integrate with Azure Monitor, Log Analytics, or export to a SIEM solution." This information is reinforced in the SC-300 traini ng under the "Implement and monitor identity governance" and "Monitor and troubleshoot Azure AD" modules, which highlight that organizations requiring extended historical data must configure diagnostic settings to forward logs to Azure Log Analytics, Azure Storage, or Event Hubs.
Hence, without additional configuration, Azure AD keeps sign-in logs for 14 days by default - after which they are automatically purged.
# Correct Answer: A. 14 days