What could be the reason why a client would prefer a key system to a PBX? (Choose all that apply.)

A.
Key systems are typically cheaper than PBX systems.

B.
Key systems can be customized solutions for stand-alone, small offices.

C.
Some small business processes are supported by unique Key systems features.

D.
Key systems support amongst others networked communication, call forward and transfer to other locations as well.

E.
All of the above.