Refer to the exhibit. 
What happens when the router stops receiving advertisements for the 10.1.2.0/24 network?
A.
The summary route will be removed from the table.
B.
The summary route will remain in the table.
C.
The more specific routes will be advertised from the table.
D.
10.1.2.0/24 will still be advertised but packets destined for it will be dropped when they reach
this router.
Explanation:
If you look very closely at the routing table output, we can conclude that R1 has “auto-summary”
enabled under the EIGRP routing process.
D 10.0.0.0/8 is a summary, 00:23:20, Null 0
Anytime the “auto-summary” is enabled under the routing process the router will install a summary
route to “null 0” as long as the router has one or more subnets within the “classful” network. In the
case above, you have two directly connected interfaces (Serial1 & Serial2) that are within the
“classful” network. Therefore, regardless of whether you leran a route via EIGRP that is in the
“classful” network, R1 will still install this summary route to “null 0”.