Why would you need to use an exterior gateway protocol?

A. You need to connect your company to the Internet.
B. You have been delegated a large number of IP addresses.
C. You want to achieve fast routing to the Internet.
D. You are dual-homed with two different ISPs.

D. The only time you need to use an exterior gateway protocol such as Border Gateway Protocol (BGP) is when you have a dual-homed connection between two ISPs. An example of this would be routing between the Internet and Internet 2. You would need to know the fastest path to the destination network via the Internet connection.