"<span>a. the size of their military" would be the best option from the list, since they greatly outnumbered the colonists and their militias. They were also far-better trained as soldiers. </span>
Hopefully these are the right answer choices, if so then your answer will be the most effective way to prevent foreigners policy would be to cut off budget support for that policy. Hopefully this helps.
I think it is D: Excise taxes
Due to the rise of industrialism, the north was mostly comprised by factories. In addition, white men in the north were literate at a higher rate than men in the South. Men in the north tended to be businessmen, scientists, etc (i.e. professionals as opposed to plantation owners/farmers like in the south). The south had a higher rate of illiteracy than the north, and was deeply influenced by an economy that depended on slavery and agriculture to thrive.