Explanation: TDMA, or Time Division Multiple Access, is a digital communication method that enables multiple users to share a single radio frequency channel. It achieves this by dividing the available transmission time into discrete, sequential time slots. Each conversation or user is assigned a specific, non-overlapping time slot within a repeating frame. Users then transmit or receive only during their designated time slot, taking turns rapidly on the same frequency. This gives the appearance of continuous communication to each user while efficiently utilizing the frequency spectrum. A) **Separate frequencies** describes Frequency Division Multiple Access (FDMA), where each conversation uses a distinct frequency channel simultaneously. B) **Separate pilot tones** are typically used for synchronization, channel identification, or control purposes, not as the primary mechanism for multiplexing separate conversations. C) **Separate power levels** are utilized for power control to manage interference or battery life, but they are not the method by which multiple conversations are multiplexed in TDMA.