It’s an odd question with an odd answer. The distances are far too great
to be correct for a line-of-sight VOR and, as a result, the issue of
convergency raises its head. If you work out the convergency properly you get
4º, therefore a conversion angle of 2º, so the absolutely correct answer for
the great circle track should be 287º. If you ignore convergency, as you
normally would, you get 285º. I've no idea why the given correct answer is 286º
apart from the horrible suspicion that, once the examiner realised
he'd asked a flawed question, he gave a choice half way between the two obvious
options.