Explanation/Reference:
Explanation:
A contained database is a database that is isolated from other databases and from the instance of SQL Server that hosts the database.
B: In the contained database user model, the login in the master database is not present. Instead, the authentication process occurs at the user database, and the database user in the user database does not have an associated login in the master database.
SQL Database and SQL Data Warehouse support Azure Active Directory identities as contained database users.
D: The contained database feature is currently available only in a partially contained state. A partially contained database is a contained database that allows the use of uncontained features.
References: https://docs.microsoft.com/en-us/sql/relational-databases/databases/contained-databases