I'd go with option D.
Buy a M760Li which comes with a new set of wheels and write off your 730d.
But more seriously it's cold right now again this weekend but winters are probably a bit late to bother. You can fit run flats sometimes and a slow leak is likely fixable. If it's a reasonable amount of tread left I'd maybe just go that route.
Give you time to do the other options when your ready and had time to consider your options better.