______in the strength of the carrier signal is varied to represent binary 1 or 0.______is a system that can map a name to an address and conversely an address to an name.()is a three-way handshaking authentication protocol that it’s packets are encapsulated in the point-to-point protocol______is an approach that enables an ATM Switch to behave like a LAN switch.______is an guided media which is made of glass or plastic and transmits signals in the form of light.
A.PPP
B.PAP
C.CHAP
D.LCP