若路由器的路由信息如下，則最后一行路由信息怎樣得到的  ( )  。
R3#show ip route
Gateway of last resort is not set
192.168.0.0/24 is subnetted,6 subnets
C    192.168.1.0 is directly connected,Ethernet0
C    192.168.65.0 is directly connected,Serial0
C    192.168.67.0 is directly connected,Serial1
R    192.168.69.0[120/1]via 192.168.67.2,00:00:15,Serial1
[120/1]via 192.168.65.2,00:00:24,Serial0
R    192.168.69.0[120/1]via 192.168.67.2,00:00:15,Serial1
R    192.168.69.0[120/1]via 192.168.652,00:00:24,Serial0
A、串行口直接連接的
B、由路由協(xié)議發(fā)現(xiàn)的
C、操作員手工配置的
D、以太網(wǎng)端口直連的