问题：

[单选] When learning a new route, if a LSA received is not found in the topological database, what will an internal OSPF router do?（）

A . The sequence numbers are checked, and if the LSA is val id it is entered into the topology database.
B . The LSA is placed in the topological database and an acknowledgement is sent to the transmitting router.
C . The LSA is dropped and a message is sent to the transmitting router.
D . The LSA is flooded imme diately out of all the OSPF interfaces, except the interface from which the LSA was received.