Does ATC use True Course or Ground Track? Reading the practice questions for PAR, I came accross this


  ATC advises, "traffic 12 o`clock." This advisory is relative to your
  A) true course
  B) ground track
  C) magnetic heading


I was inclined to got for A) but isn't that the same as B)?
Neither are defined in PHAK glossary.
A heading is the direction the plane's nose is pointed. A course is the direction it is actually traveling. The difference between the two depends on wind.

A true heading or course is corrected for magnetic variation; a magnetic heading or course is not.

Track and course are often used interchangeably, but technically a "course" refers to what you intend to do while a "track" refers to what you actually do.

ATC can only see your ground track on their radar screens, so logically that would be their reference for traffic advisories--and you may look in the wrong direction if you don't realize that, which I suspect was the point of the question.