Multiplex refers to:

• A. A single communications channel
• B. Encrypted voice only
• C. Transmitting audio and data signals through more than one channel
• D. Using only broadcast channels

Answer: (C)

Multiplexing is the technique of combining multiple signals so they can be transmitted together over a shared medium. By carrying audio and data signals through more than one channel, multiple streams can be sent at once and later separated at the receiving end. This increases transmission efficiency and capacity. Different methods achieve this, such as time-division multiplexing, where signals use different time slots on the same path, and frequency-division multiplexing, where signals occupy distinct frequency bands. That’s why describing multiplexing as transmitting audio and data signals through more than one channel best captures the idea. The other options describe a single channel, a restricted use (encrypted voice only), or broadcast-only scenarios, which don’t reflect the fundamental concept of combining multiple signals for transmission.