Which four of these key points should be considered during implementation of PPPoA architecture？（）
- Athe number of subscribers that will be serviced currently and in the future because this affects the number of required PPPoA sessions
- BThe types of applications that the NSP offers to the end subscriber
- CThe capacity of ATM and Frame Relay interworking on the NSP
- Din the case of more than one user， whether all users need to reach the same final destination orservice，or they all have different service destinations
- EWhether the service provider or the final service destination is providing the IP address to the CPE of the subscriber