The correct answer is C, as protective tariffs was a main provision of the American System.
The American System was an American mercantilist economic plan based on the ideas of the American School of Alexander Hamilton, developed later by Friedrich List, which proposed high tariffs to support public works (such as road construction), a national bank to promote productive companies, and create a national currency. It was assumed that this program would allow the United States to grow and prosper by providing defense against dumping of cheaper foreign products, mainly from the British Empire.
