For What Two Purposes Does the Ethernet Protocol Use Physical

Multiple Choice

For what two purposes does the Ethernet protocol use physical addresses?

A) to uniquely identify devices at Layer 2
B) to allow communication with devices on a different network
C) to differentiate a Layer 2 frame from a Layer 3 packet
D) to establish a priority system to determine which device gets to transmit first
E) to allow communication between different devices on the same network
F) to allow detection of a remote device when its physical address is unknown