the answer is B: increasing trade with other nations
I believe that the system that is being spoken of is imperialism.
Imperialism is a nations desire to claim territory through economic control through both diplomatic and violent tactics. Although militarism has a very similar definition, it only relies on military control and not any diplomatic influence.
I hope this is what you’re looking for :)
I think that the answer to your question is either A or C but I'm going towards A
A................................................
I am pretty sure that is is the attack on Pearl Harbor