The correct answer is D, as States can influence the policies of the federal government by trying out policies that might later affect the entire Nation. If the State carried out policies within its territory that would indirectly affect the rest of the states, it would not be exceeding its powers, since its policies would only apply directly to its territory. In this way, it would influence federal policies, since the federal government should pay attention to the matter because it would indirectly affect several states.
Option A is not correct because foreign policy is a Federal government matter.
Options B and C are also uncorrect as they imply an overreach on the part of the State when legislating for the whole Nation
, since they can only pass laws for their own territories.
