Which is not a reason that Internet Service Providers prefer to use PPP over Ethernet (PPoE)?（）

• A、access control and billing can be done on a per-user, rather than a per-site basis
• B、supports Link Fragmentation and Interleaving 
• C、provides the ability to connect a network of hosts over a simple bridging access device
• D、provides a consistent means of authenticating users (RADIUS for example)