What Was One of the Advantages of the "American System

What was one of the advantages of the "American system" of manufacturing?

A) Inventors would have more time to develop their inventions slowly.
B) Manufacturers would have a convenient way of excluding outside investors.
C) Foreigners would have no way of copying American machines.
D) Damaged parts could be replaced easily.
E) American craftsmen could demonstrate their skills to the British.