为转发某个UDP请求的广播通信，必须使用下列的哪一个命令（）。

A.SHOW IP ROUTE
B.show ip redirect
C.change ip route
D.no ip route

A.Select either of the two routes at random，with no preference for one over the other
B.Select the route that has a lower administrative distance value
C.Select the route tha thas a higher administrative distance value
D.Place both the routes in the routing table

A.DNS-Dynamic Naming Service
B.UDP-User Datagram Protocol
C.DHCP-Dynamic Host Configuration Protocol
D.TFTP-Trivial File Transfer Protocol