单项选择题

A. Both outgoing and incoming routing updates on R1 will be permitted because the d istribute - list 20 out Serial0/0 command cannot be used with association with the outgoing interface.
B. All incoming routing updates from R2 will be suppressed, but the outgoing updates will continue to be sent.
C. Both outgoing and incoming routing up dates on R1 will be stopped because of the passive - interface Serial0/0 configuration statement.
D. All outgoing routing updates from router R1 to router R2 will be suppressed, but the inbound updates will continue to be received.