D. Increased migration to the United States
An important duty of the president is "negotiating treaties," since this duty falls to the executive branch, and the president is in charge of this branch (although this specific task is often delegated to the State Department).
C. 'pax' means peace in latin, and 'Romana' means Roman, so it literally translates to "Roman Peace", which was a time of create peace and a time when the cultures flourished. :)
