Which of the following must be specified regarding communications during a flight request?

The requirement to specify the means of two-way communications with air traffic control is fundamental for safe flight operations. Effective communication with air traffic control (ATC) is essential for maintaining situational awareness, coordinating air traffic movements, and ensuring safety during all phases of flight.

Establishing a reliable method of two-way communication enhances the pilot's ability to receive instructions, report their position, and respond to ATC queries. This specification is particularly critical in busy airspace environments where clear and instantaneous communication may impact flight safety. It ensures that pilots are equipped to handle unexpected situations or changes in instructions from ATC.

The other options, although they may play a role in communication protocols, do not directly address the core requirement of establishing effective communication with ATC, which is a priority for compliance and safety during a flight operation.