The description of the LSA header information in the AS-External-LSA of OSPF, which is wrong?

The description of the LSA header information in the AS-External-LSA of OSPF, which is wrong?
A . Link State ID indicates the destination network address.
B . Advertising Router indicates the router ID of ASB
D . Net mask indicates the network mask of the destination network segment.
E . Forwarding Address is always 0.0.0.0.

Answer: D