You have a server that contains a default SQL Server 2005 instance. You need to install a
SQL Server 2008 instance for a new application on the same server. The new application
requires SQL Server 2008 functionality.
You need to ensure that both database instances are available for their respective certified
third-party applications. The existing application environments remain unchanged.
What should you do?

A.
Install SQL Server 2008 as the default instance.

B.
Install SQL Server 2008 as a named instance.

C.
Upgrade the SQL Server 2005 application to use SQL Server 2008.

D.
Upgrade the SQL Server 2005 instance to a SQL Server 2008 instance.