What is the altitude range for cruising as per IFR regulations?

The specified altitude range for cruising under IFR regulations is indeed based on the minimum IFR altitude and the cruise altitude applicable to the flight. Minimum IFR altitude is essential as it ensures safe obstacle clearance and compliance with air traffic control requirements. The cruise altitude may vary depending on the route, aircraft performance, and air traffic conditions.

According to the regulations, during instrument flight, pilots must operate within the minimum IFR altitude, which provides a safety margin above terrain and obstacles, while also operating at an assigned cruise altitude determined by ATC or by the pilot's planned route. This combination ensures that the flight remains in compliance with safety regulations while optimizing flight efficiency.

Understanding this altitude range is vital for maintaining safety and compliance with federal aviation regulations, hence making this the correct answer for cruising altitudes under IFR conditions.