There are three IS-IS routers on a Gigabit Ethernet seg...
There are three IS-IS routers on a Gigabit Ethernet segment: Router A, Router B, and Router C. Each router is configured in the same area and each routers Gigabit Ethernet interface is configured for Level 1-only. Router A is the Designated Intermediate System (DIS). Each routers IP address on that segment is:
Router A: 10.1.1.1/24
Router B: 10.1.1.2/24
Router C: 10.2.2.1/26
Which statement is true about all the adjacencies that exist on that LAN?（）
A. No routers are adjacent with each other.
B. Only Router A and Router B are adjacent at Level 1.
C. Only Router A and Router B are adjacent at Level 2.
D. All three routers are adjacent with each other at Level 1.
