Explanation:
Box 1: Yes
The storage account and SQL server are in the same region, ensuring compliance with the requirement that audit logs be stored in a storage account in the same region as the server.
Box 2: No
Since the regions are different, the audit logs cannot be stored in storage2 for SQLdb2.
Box 3: No
Since the regions are different, the audit logs cannot be stored in storage2 for SQLdb3.
Note: While configuring auditing for azure sql db, azure portal only will show storage accounts which are in same region. Both standard and premium storage accounts can be used but they need to be in same region as db.
Reference:
https://docs.microsoft.com/en-us/azure/azure-sql/database/auditing-overview#auditing-limitations