Which of the following correctly describes the roles of devices in a WAN?

As a network administrator, you will need to decide on the appropriate network devices to use. Which of the following correctly describes the roles of devices in a WAN? (Choose three)

A.
A CSU/DSU terminates a digital local loop.

B.
A modem terminates a digital local loop.

C.
A CSU/DSU terminates an analog local loop.

D.
A modem terminates an analog local loop.

E.
A router is commonly considered a DTE device.

F.
A router is commonly considered a DCE device.

Explanation:
Layer 2 switching is considered hardware-based bridging because it uses specialized hardware called an application-specific integrated circuit (ASIC). ASICs can run up to gigabit speeds with very low latency rates.
A router is commonly considered to be a DTE device, while a CSU/DSU is considered the DCE device.
Switches usually have higher port number then bridge. Generally bridges have two ports. Both operates on Data link layer.