A subscriber’s DSL service is configured as PPPoA. The subscriber’s DSL modem is trained, but the subscriber can not access the internet (can not ping network addresses or reach web servers). Initial troubleshooting shows that a PPP session is open (active) in the DSL modem and aggregator. Based on these conditions and the symptom, what is a possible cause of this problem?

A.
An incorrect PVC (VPI/VCI) was provisioned between the DSLAM and the ATM switch.

B.
An incorrect PVC (VPI/VCI) was provisioned between the ATM switch and the router.

C.
An incorrect PVC (VPI/VCI) was provisioned between the DSLAM and the DSL modem.

D.
There is a problem in the physical connection or configuration between the DSL modem and the CPE.