what two purposes does the Ethernet protocol use physical addresses?

For what two purposes does the Ethernet protocol use physical addresses? (Choose two.)

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

Explanation:
In computing, a physical address, also real address, or binary address, is the memory address that is electronically (in the form of binary number) presented on the computer address bus circuitry in order to enable the data bus to access a particular storage cell of main memory.