Step 1: Multiplexing Defined.Multiplexing is a method in telecommunications and networking that combines multiple signals or data streams into a single shared channel. Its main purpose is to maximize the use of limited resources, such as a fiber optic cable.
Step 2: Option Analysis.\[\begin{array}{rl} \bullet & \text{(A) It is a technique *used* in telephone technology, but not the technology itself.} \\ \bullet & \text{(B) Multiplexing enhances efficiency and can boost transmission quality by enabling multiple signals to share a high-capacity channel, a significant advantage.} \\ \bullet & \text{(C) This contradicts the objective.} \\ \bullet & \text{(D) This describes simplex communication, not multiplexing.} \\ \end{array}\]
Step 3: Conclusion.Therefore, a primary benefit and objective of multiplexing is enhancing transmission quality through efficient use of high-quality channels.