How are routers managed with interior gateway protocols?

A. Routers are grouped into autonomous systems.
B. Routing protocols are redistributed between ASs.
C. All routers use the same interior routing protocol.
D. All network IDs are advertised with the same autonomous system number.

A. Routers are grouped into the same autonomous system (AS). When they are within the same AS, they can exchange information such as routes to destination networks and converge their routing tables.