Talk about a wide range of possible answers! I assume you're not referring to Melbourne's Deakin University course D338, Bachelor of International Studies?
Oops, that's a blow-I thought my answer was a joke, but guessed as you (and I) are in France, where the Dxyz becomes the Dabc without any warning in some cases. I'd better think something up, but pleas allow me a night to do so.
Ok here goes. Who is the only sportsman (so far) to have played in the World Cup in 2 different sports. Completely different that is, not like snooker and billiards/pool or bridge and whist.
If both sports involve a ball, (not a given), the balls are of different dimensions. Any nationality. Also, it occurs to me that for example high jump and pentathlon might be thought of as different. Well no, IF athletics is involved, all athletic events are included in the sport of athletics. But athletics and tiddlywinks are different sports- just to be helpful.
Australia's Ellyse Perry? Helped Australia win the Women's ICC World Cup in 2013 - and played & scored in the 2011 FIFA Women's World Cup quarter final.
A rugby union ball has slightly different dimensions to that used in rugby league - so is it someone who changed ? Maybe Jonathan Davies who played league for Wales and Great Britain and union for Wales ?
Sorry I didn't know the ball was different in league and union, so I hoped my definition would indicate 2 different sports more effectively. Not Jonathan Davies. A clever idea though, great sportsman ( good man too). If a ball is involved, it is round-mostly. Enough to eliminate bowls!
Was it Viv Richards ? Played for Antigua & Barbuda in the World Cup Qualifying rounds in football and for the West Indies in cricket.
Excellent! Well done. It surprised me. Sorry I have only just seen your answer-we are an hour ahead in France (oh of course you are too!) Anyway, we have a signal about as reliable as our broyeur -better not to ask. The delights of la campagne in central France. Still at least they aren't leaving the EU. Anyway, over to you.