You have a Level 1-only router (Router A) in IS-IS area 49.0001. How does Router A learn how to get to IP prefixes in other areas?（）

A.Router A must have a Level 2 adjacency with the Level 1/Level 2 router in area 49.0001.

B.The Level 1/Level 2 router in area 49.0001 sets the attached bit in the Level 1 link-state PDU (LSP) it floods into area 49.0001.

C.The Level 1/Level 2 router in area 49.0001 sets the attached bit in the Level 2 LSP it floods into area 49.0001.

D.The Level 1/Level 2 router in area 49.0001 advertises these prefixes into area 49.0001 using a Level 2 LSP it floods into the area.