Which three statements are correct about the IEEE 802.3af Power over Ethernet standard? (Choose three)
A.
It defines a port that acts as a power source to be a PSE
B.
It defies a powered device to be a PDE
C.
It defies how a powered device is detected
D.
It defies three methods of delivering Power over Ethernet to the discovered powered device
E.
It describes five power classes to which a device may belong
F.
It defines power class 0 as being reserved for future use