Interoperability considerations include:

• A. Mobile to mobile/base, base to mobile, ham radio, citizen band (CB) radio
• B. Cellular networks only
• C. Satellite communications
• D. Public address systems

Answer: (A)

Interoperability in public safety means you can communicate across different systems and modes, not just a single network. The best choice shows the wide range of tools that enable cross‑agency and cross‑mode contact: mobile units talking to other mobiles and to base stations, base stations reaching out to mobiles, and using alternative radio services like amateur radio and citizen band to stay connected when primary networks are busy or down. Relying only on cellular networks isn’t sufficient because these networks can fail or become overwhelmed in emergencies, and satellite communications, while useful in some contexts, don’t guarantee broad, day-to-day two‑way interoperability across agencies. Public address systems aren’t designed for two‑way emergency communications between responders, so they don’t provide the necessary interoperable capability.