HOTSPOT
Your company has two offices. The offices are configured as shown in the following table.
The offices connect to each other by using a WAN link that has a latency of more than 700 ms.
You plan to deploy an Exchange Server 2013 organization to meet the following requirements:
Ensure that users can access their mailbox if the WAN link fails.
Ensure that users can access their mailbox if a single server fails.
Ensure that users can access their mailbox if a single database fails.
You recommend deploying one or more database availability groups (DAGs) and mailbox database
copies.
You need to identify which design meets the requirements for the planned deployment.
Which design should you identify?
To answer, select the appropriate design in the answer area.
Answer: 
I agree with this answer, either way whichever DAG fails the user mailboxes will be available in each site still.
This question does NOT mention SITE-FAILURE!
There is no(!) good answer if this must be ensured!
So you have to choose the best answer is with DAG1 and DAG2 and a 1 witness per Site.
(THIS IS A TRICKY QUESTION)