You need to ensure that the login for the ticketing application cannot access other production databases

You administer a single server that contains a Microsoft SQL Server 2012 default instance on which
several production databases have been deployed.
You plan to install a new ticketing application that requires the deployment of a database on the
server. The SQL login for this application requires sysadmin permissions.
You need to ensure that the login for the ticketing application cannot access other production
databases.
What should you do?

A.
Use the SQL Server default instance and enable Contained Databases.

B.
Use the SQL Server default instance and configure a user-defined server role. Add the login for the
ticketing application to this role.

C.
Install a new named SQL Server instance on the server.

D.
Install a new default SQL Server instance on the server.