Which frequency is primarily used by pilots for communication at an uncontrolled aerodrome?

Pilots primarily use the Aerodrome Traffic Frequency for communication at an uncontrolled aerodrome because it is specifically designated for the purpose of managing air traffic in and around such airports. This frequency allows pilots to announce their intentions, such as taking off, landing, or taxiing, to each other, thereby enhancing situational awareness and safety.

At uncontrolled aerodromes, there is no air traffic control to provide guidance, so it becomes the responsibility of pilots to communicate with each other. Using this frequency helps ensure that all aircraft are aware of each other's positions and intentions, which is crucial for avoiding collisions and ensuring a smooth flow of traffic on the ground and in the airspace.

The other choices pertain to specific roles or situations that are not relevant to communications at uncontrolled aerodromes. Clearance Delivery is used at controlled airports for pilots to receive their flight clearances, General Broadcast Frequencies are typically broader and may cover various purposes not specific to aerodrome traffic, and Terminal Arrival refers to frequencies associated with controlled terminals and coordinated arrival procedures rather than uncontrolled aerodrome operations.