Which of the following is a requirement of setting up SQL Server AlwaysOn High Availability?

Which of the following is a requirement of setting up SQL Server AlwaysOn High Availability?

• Windows Server Failover Clustering (WSFC)
• Network Load Balancing (NLB)
• Windows Internal Database
• Internet Information Services (IIS) 

EXPLANATION

AlwaysOn requires that failover clustering is installed on each node and that the nodes are joined to the cluster prior to enabling AlwaysOn High Availability on the SQL server. AlwaysOn has to be enabled through the SQL Server Configuration Manager prior to being configured in SQL Server Management Studio (SSMS).