Refer to the exhibit. Which two statements about the IS-IS topology are true? (Choose two.)
A. R1 and R4 are Level 2 neighbors.
B. All four routers are operating as Level 1-2 routers.
C. All four routers are operating as Level 2 routers only.
D. All four routers are operating as Level 1 routers only.
E. R1 and R2 are Level 2 neighbors.
default session IS-IS is L1-2, only R1 and R2 is neighbors, not directly neighbors R1 and R4
The ansewer corret B, E