A: Please read and double-check the question again. The question states to not configure subinterfaces.
Q: What ATM encapsulation should I use?
A: This is a back-to-back configuration and the backbone is using the default encapsulation.
Q: Do you want me to configure "broadcast" under my ATM interfaces?
A: You need to determine what type of traffic/protocols will use the ATM network.
Q: I have my ATM configured and the map statement too, but I still am not receiving any routes from the backbone. Can I verify if the backbone is acceptable?
A: Yes, I can verify. But also please double-check your configuration to ensure that nothing is missing.