Which of the following is a requirement for IFR operations in airspace A?

The requirement for IFR operations in airspace A emphasizes that the aircraft must be equipped with Mode C transponder and ADS-B capabilities, alongside being IFR rated. Airspace A is classified as controlled airspace where IFR traffic has priority, and the presence of a Mode C transponder is essential for the purpose of providing air traffic control (ATC) with altitude information, which is critical for maintaining safe vertical separation between aircraft.

In controlled airspaces like Class A, aircraft must operate under IFR and maintain communication with ATC, which includes being properly equipped and rated for IFR operations. The requirement for a Mode C transponder ensures compliance with traffic management and safety protocols, as it allows the ATC to observe and track the aircraft's position and altitude accurately.

Other options do not fully address the specific requirements for IFR operations in airspace A. For example, while control tower clearance and two-way radio communication are indeed important for safety and operational compliance in controlled airspaces, they do not encapsulate the specific equipment requirement as identified in option C. VFR conditions are also not applicable as IFR operations are performed under instrument flight rules, regardless of the weather conditions. Thus, the qualifications presented by option C are the most aligned with current regulations for IFR operations in Class