I choose the van, because I think it's the most likely to contain a lighter, a common item acquired early game in other versions of this. I'd suspect food in the tree and maybe silver, a gun, or water purification tablets in the shop.
Of course, it might just be that this round is for killing people off. In which case, this seems the most likely to bring death... but I think I've figured out that the first few rounds involve resource acquisition.