In which circumstances can an IFR aircraft be vectored?

An IFR aircraft can be vectored within the controller's jurisdiction unless explicitly coordinated otherwise. This means that as long as the aircraft is under the controller's responsibility and there are no special restrictions or requirements set by ATC, the controller has the authority to provide traffic advisories and directions to ensure safe and efficient operations. Vectors are often necessary for managing traffic flows, particularly in busy airspace where controllers need to guide aircraft around obstacles, other traffic, or towards specific approach paths.

Other scenarios as suggested by the incorrect options would typically not be appropriate for vectoring. For instance, vectored aircraft outside controlled airspace could endanger safety, and vectoring an aircraft below minimum appropriate altitude could violate safety regulations. Additionally, vectoring an aircraft not authorized by ATC would undermine the air traffic control's procedures and potentially compromise safety in the airspace system. Therefore, it's crucial that IFR aircraft are managed within the defined parameters of controller jurisdiction to maintain operational integrity.