The correct answer is A) the Moving Assembly Line.
The phrase that belongs in the center of the web is the Moving Assembly Line.
This refers to the moving assembly line that Henry Ford started to use on December 1, 1913. He installed the moving assembly line in his fabric for the mass production of a car. This was a great innovation for the time because it reduced the time needed to elaborate an automobile. It used to take 12 hours. And with the moving assembly line already working, it took 30 minutes. That is how produced his famous and simple “Model T”.