You work as the database administrator at Domain.com. The Domain.com network consists of a single Active Directory domain named Domain.com. All servers on the Domain.com network run on Windows Server2003 and all client computers run Windows XP Professional. The Domain.com network contains two SQL Server 2005 database servers that are configured in a cluster with two nodes named NodeA and NodeB. NodeA hosts a default database instance named MSSQLSERVR.
Domain.com wants to implement another SQL Server 2005 instance for a database named Sales_DB. Sales_DB will store sales data for the company. All Domain.com users will require access to the Sales_DB database. You have been instructed to create the SQL Server 2005 instance for the Sales_DB database on NodeA. You need to ensure that all users will be able to connect to the Sales_DB database.
What should you do?

A.
Run the SQL Server 2005 Setup utility on NodeA and select a Named Instance for the Sales_DB database.

B.
Run the SQL Server 2005 Setup utility on NodeA and select the Default Instance for the Sales_DB database.

C.
Move the existing instance from NodeA to NodeB. Run the SQL Server 2005 Setup utility on NodeA. Select the Default Instance and accept the default instance name

D.
Run the SQL Server 2005 Setup utility on NodeB and select a Named Instance for the Sales_DB database.

Explanation:
The default instance is named MSSQLSERVER. This instance name is already in use on NodeA; therefore you should use a Named Instance.
Incorrect Answers:
B: You cannot use the Default Instance as the default instance is named MSSQLSERVER and is already in use.
C: You do not need to move the existing instance as you can install up to 50 instances on a SQL Server 2005 database server.
D: You need to install the instance on NodeA not NodeB. You can install a new instance on NodeA if you use a Named Instance.