You administer a Microsoft SQL Server 2012 failover cluster that contains two nodes named
Node A and Node B. A single instance of SQL Server is installed on the cluster.
An additional node named Node C has been added to the existing cluster.
You need to ensure that the SQL Server instance can use all nodes of the cluster.
What should you do?

A.
Run the New SQL Server stand-alone installation Wizard on Node C.

B.
Run the Add Node to SQL Server Failover Cluster Wizard on Node C.

C.
Use Node B to install SQL Server on Node C.

D.
Use Node A to install SQL Server on Node C.

Explanation:
http://technet.microsoft.com/en-us/library/ms191545.aspx
To add a node to an existing SQL Server failover cluster, you must run SQL Server Setup on
the node that is to be added to the SQL Server failover cluster instance. Do not run Setup on
the active node.
The Installation Wizard will launch the SQL Server Installation Center. To add a node to an
existing failover cluster instance, click Installation in the left-hand pane. Then, select Add
node to a SQL Server failover cluster.