Need to maintain transational consistency of the data across both servers, need to achieve these goals without manual intervention

I got this question about MS SQL Server 2012 administration, two production servers in the same data center. You need to ensure that database remains available if a catastrophic server failure or a disk failure occurs.

You need to maintain transactional consistency of the data across both servers. You need to achieve these goals without manual intervention.

The correct answer for the above question is

>>

Two servers configured on the same subnet

SQL Server Availability Group configured in Synchronous-Commit Availability Mode

<<

But I think the correct answer should be

>>Two servers configured in Windows Failover Cluster in the same data center SQL Server configured as a clustered instance<<