Which network technology addresses these customer business needs: shrinking budgets and IT staffs, more complex networks, and an increased need for network security?（）

A.Stores data on the network and connects the local-area network (LAN) to the wide-area network (WAN)
B.Routes traffic down alternative paths and connects the local-area network (LAN) to the wide- area network (WAN)
C.Broadcasts data to all devices that are connected to it across the local-area network (LAN) and wide-area network (WAN)
D.Reads Media Access Control (MAC) addresses to forward messages to the correct location and connects the local-area network (LAN) to the wide-area network (WAN)

A.Host
B.Switch
C.Printer
D.Repeater

A.Layer one
B.Layer two
C.Layer three
D.Layer four