For airplane B with 280 degrees set in the course selector, the VOR indications will correspond to which instrument?

When using a VOR (VHF Omnidirectional Range) navigation system, the course selector allows the pilot to set a desired course or heading. In this scenario, an airplane is set to a course of 280 degrees. The VOR indicator will show the relationship between the aircraft’s current heading and the selected course.

The instrument that corresponds to the 280-degree setting on the VOR will reflect the radial from the VOR station that aligns with the aircraft’s heading towards or away from that radial. When the pilot selects 280 degrees, the VOR instrument will indicate the aircraft’s position in relation to a navigational path that is 280 degrees from the VOR station.

This means that for airplane B with the set course, the instrument that displays the required course heading of 280 degrees in combination with the required navigational information and correct radial alignment is Instrument 3. This instrument would accurately reflect the aircraft's position, deviation from the desired course, and guidance toward or away from the 280-degree radial, which is crucial for navigation and maintaining the intended flight path.