The PassGuide network consists of a series of routers that are all configured for IBGP. Which one of the following IBGP characteristics is true（）

• A、The IBGP routers must always be fully meshed.
• B、The IBGP routers can be in a different AS.
• C、The IBGP routers must be directly connected.
• D、TThe IBGP routers do not need to be directly connected.
• E、None of the other alternatives apply are true