You work as a network administrator at ABC.com. The ABC.com network consists of an Active Directory Domain Services domain named ABC.com. All servers on the network run Windows Server 2008 R2. The client computers run a mix of Windows XP Professional and Windows 7 Enterprise.

A Windows Server 2008 R2 server named ABC-RDS1 runs the Remote Desktop Session Host role and the Microsoft Application Virtualization (App-V) 4.6 client.

You use App-V to publish a custom Sales application named ABC-SalesApp on ABC-RDS1.

You want to provide external Sales users access to ABC-SalesApp. You provide the external Sales users a Remote Desktop Protocol file that enables them to use the Connect From Anywhere feature to access ABC-SalesApp on ABC-RDS1.

You now need to configure the corporate firewall to allow the external connections to ABC-RDS1.

Which port should you open on the firewall?

A.
You should open HTTP port 80.

B.
You should open RTSP port 554.

C.
You should open HTTPS port 443.

D.
You should open RDP port 3389.