单项选择题

A.路由器A的inbound sa与路由器B的inbound sa相同,路由器B outbound sa与路由器A outbound sa相同
B.路由器A和B的inbound saoutbound sa均相同
C.路由器A的inbound sa与路由器B的outbound sa相同,路由器Binbound sa与路由器A outbound sa相同
D.路由器A的inbound sa与outbound sa相同,路由器B的inbound sa与outbound sa相同