单项选择题

A. R 4 becomes the successor for Network A and will be placed in the routing table. R2 becomes the feasible successor for Network A
B. R4 becomes the successor for Network A and will be included in the routing table. No feasible successor will be selected a s the advertised distance from R2 is higher than the feasible distance
C. R2 becomes the successor and will be placed in the routing table. R4 becomes the feasible successor for Network A
D. R2 becomes the successor and will be placed in the routing t able. No feasible successor will be selected as the reported distance from R4 is lower than the feasible distance