Answer:
A) Full-duplex
Step-by-step explanation:
In data communication and networks, duplex refers to transmissions that occurs in two directions. Two types of this transmission is recognized, these are; full-duplex and half-duplex.
In a full-duplex, the data transmission in the two directions can occur at same time, the popular example of this is the cellular phone as the two persons on a phone can speak and hear each other both ways at the same time. The half-duplex on the other hand allows only a one-way data transmission at a time, the popular example is the walkie-talkie, only one party talks at a time.