Mode 3 of the military IFF system is identical to which IFF mode of the civil system?

Mode 3 of the military Identification Friend or Foe (IFF) system is indeed identical to Mode A of the civil system. Both modes are used for basic identification purposes when an aircraft is in controlled airspace. They allow air traffic control and other aircraft to distinguish between civil and military aircraft.

Mode A transmits a 4-digit code that identifies the aircraft to air traffic controllers, and Mode 3 performs a similar function within the military context, using a compatible code format for identification. This alignment allows for efficient tracking and identification of aircraft, facilitating safety in operations where military and civil air traffic may interact.

The other options represent different functionalities within the IFF system. Mode B, for example, involves altitude reporting in addition to identification, and Mode C provides a more complex set of information, including pressure altitude data. Mode D serves specific needs in a different context, further extending capabilities beyond simple identification.