Based on the partial outputs in the exhibit, what could be the problem?

Refer to the exhibit. From RouterA, a network administrator is able to ping the serial interface of RouterB but unable to ping any of the subnets attached to RouterB. Based on the partial outputs in the exhibit, what could be the problem?

A.
EIGRP does not support VLSM.

B.
The EIGRP network statements are incorrectly configured.

C.
The IP addressing on the serial interface of RouterA is incorrect.

D.
The routing protocol has summarized on the classful boundary.

E.
EIGRP has been configured with an invalid autonomous system number.