They started using billboards i believe hope that helps
Well, there are a few reasons, but I will give you an advantage, where you can find the disadvantage from it.
Europe has a small coastline, but with it, there's a sea that leads straight to north America. That means there's easy transport of goods.
Your answer would be C, mainly because the soil near a waterway is very fertile, and before cars, boats were a cheap, easy way of transit.
