Read this and answer the question. If the question is unanswerable, say "unanswerable".

For customers with more demanding requirements (such as medium-to-large businesses, or other ISPs) can use higher-speed DSL (such as single-pair high-speed digital subscriber line), Ethernet, metropolitan Ethernet, gigabit Ethernet, Frame Relay, ISDN Primary Rate Interface, ATM (Asynchronous Transfer Mode) and synchronous optical networking (SONET).

What is available to customers with less demanding requirements?
unanswerable