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:<br /> Router A: 10.1.1.1/24<br /> Router B: 10.1.1.2/24<br /> Router C: 10.2.2.1/26<br /> 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.