When must students coordinate their departure clearances with the Radar Controller?

The correct choice is based on the need for efficient communication and coordination in air traffic management. Departure clearances must be coordinated with the Radar Controller immediately after they are issued. This ensures that the controller is aware of the aircraft's clearance and can provide any necessary additional instructions, including any restrictions or traffic information that may impact the departure.

Prompt coordination helps maintain safety and efficiency in the airspace, enabling the Radar Controller to effectively manage aircraft movements on the ground and during the initial climb. It’s important for students to grasp that this immediate communication is part of the standard operating procedures to minimize the risk of miscommunication and enhance overall situational awareness in busy airspace.

Other options, such as coordinating before the briefing starts or only at various stages of the flight, do not reflect the urgency and immediacy required in coordinating with the Radar Controller right after the issuance of clearance.