What does the suffix 'D' indicate about an aircraft's equipment compatibility?

The suffix 'D' in the context of aircraft equipment compatibility specifically designates that the aircraft has no transponder but does have Distance Measuring Equipment (DME). This is an important designation for air traffic control as it provides crucial information regarding the aircraft's navigation capabilities. Knowing that the aircraft is equipped with DME allows air traffic controllers to understand how the aircraft can navigate and operate within controlled airspace, especially in terms of position reporting and distance determination, while also being aware that it does not have a transponder to communicate its location electronically.

The other options indicate different configurations and capabilities related to transponders and navigation systems, which do not accurately reflect what the 'D' suffix signifies. In this case, it's essential for air traffic control to have precise knowledge of an aircraft's equipment to ensure safe and efficient operations in the airspace.