HOTSPOT
You have an Exchange Server 2010 organization.
You plan to upgrade to Exchange Server 2016.
You have two Active Directory sites configured as shown in the following table.
You have five servers configured as shown in the following table.
You have three users who have mailboxes configured as shown in the following table.
You have the following configurations:
The OWA virtual directory ExternalURL on CAS01 is https://mail.brussels.contoso.com/owa.
The OWA virtual directory ExternalURL on CAS02 is $null.
The OWA virtual directory ExternalURL on EX03 is https://mail.contoso.com/owa.
All users connect to https://mail.contoso.com/owa to access Outlook on the web.
For each of the following statements, select Yes, if the statement is true. Otherwise, select No.
Hot Area:
Answer: 
Yes, No, yes: but not sure.
This kind of looks like a trick question. I have a feeling it’s: No, No, Yes. User1: Brussels is not internet-facing. Even if an OWA externalURL is set, it doesn’t matter. I think User1 will be redirected to CAS02.
User1: No. they will be proxied
User2: No. they will be proxied
User3: No. they will be redirected
This question has changed anyways, as per q19 in v4, so these answers are moot
https://technet.microsoft.com/en-us/library/bb310763(v=exchg.141).aspx
Yes – Redirection as the CAS is defined with an external URL
No – Intersite Proxying to CAS02
No – User 3 is on Ex03 itself, local proxy to the copy handling mailbox.
Thanks for your help! It looks like the question was updated with the one in q19 anyways?