A. A type 3 (stub) link is advertised for a multi-area adjacency.
B. Configuring a multi-area adjacency allows the corresponding link to be considered an interarea link, so it will be less preferred over an intra-area link.
C. One logical interface will be a primary link, and the other configured as a secondary link; the secondary link will be established as an unnumbered point-to-point interface.
D. A DR and a BDR will be elected over the secondary interface, because it is not point-to- point.