If you look at the question, it only asks about make and vehicle (a specific vehicle that is serialized). This means that a vehicle with VIN #3278 can only be manufactured by one company (make). A single vehicle with that VIN can’t be made by both Toyota and Ford, it can only be made by Toyota or Ford (or any other make, it can only have one tho). Does that make sense? If the relationship were vehicle 1 to make many, then you could end up having a vehicle with VIN #8765 being linked to Ford and Chrysler, which doesn’t make sense. It would also mean that all of those companies could only make that one singular vehicle, and no more, which also doesn’t make sense. However, with a relationship of vehicle many to make 1, it means that each make could make as many singular vehicles as they wanted, but only one company could make that singular vehicle.