The correct answer is A) to show that his plan will help all Americans.
Clay listed all of the different people who will benefit from the American System to show that his plan will help all Americans.
We are talking about the economic system proposed by one of the most important members of the US Congress: Henry Clay. Once the War of 1812 had ended, Clay developed the American System, an economic program designed to basically protect American products from foreign products that could represent competition for American goods. He wanted no competition at all that could rivalize or represent a risk for US manufacturers. That is why he proposed that the US government established tariffs on all importations.
