The correct option is C The realization that engaging in expansion and imperialism was going to lead to foreign entanglements and require large military expenditures.
The long-standing American policy dating fro George Washington's farewell address and the Monroe doctrine was to stay uninvolved in European and the US had remained neutral in the face of almost non-stop conflict in Europe. This seemed to keep the US focus on the larger world and the Americans were certainly more interested in the events at home. One group interested in overseas expansion was the business community as they saw this as an opportunity for new markets, new places to acquire raw materials, and possibly a place to acquire cheap labour.