Which of the following entities recommends transmit/receive channels and other parameters for auxiliary and repeater stations?

The correct answer highlights the function of the Frequency Coordinator, which is essential for ensuring orderly and efficient use of the radio frequency spectrum among amateur radio operators, particularly for auxiliary and repeater stations. Frequency Coordinators are often associated with specific geographical areas and work within their communities to recommend channels and parameters that help avoid interference between stations. They assess the needs of different operators and coordinate frequency usage to provide stability within the amateur radio service.

The role of the Frequency Coordinator is especially important as multiple users may want to operate on similar frequencies; thus, having an organized approach helps maintain effective communication without unwanted interference.

In contrast, the other options do not specifically deal with recommending channels for auxiliary and repeater stations. The Frequency Spectrum Manager is involved in broader spectrum management but does not specialize in amateur radio coordination. The FCC Regional Field Office handles regulatory compliance and enforcement rather than frequency coordination. The International Telecommunications Union focuses on global telecommunications standards and regulations, which is too wide-ranging for local amateur frequency coordination.