I think it might be d although I am not entirely sure.
Answer:
restriction of interest to a narrow sphere; undue concern with local interests or petty distinctions at the expense of general well-being.
His steel company dominated the U.S. steel market because it made good steel at low expenses. That was possible because he used high-quality equipment and gave workers low wages. He helped to make U.S steel some of the best in the world.
Because the germans sunk the lusitania, they blocked trade routes and they killed americans
