Question

an official government order that limits trade with another nation to punish or pressure that nation in some way is known as
an act of war.
an embargo.
isolationism.
appeasement.

Explanation:

An embargo is a government - imposed restriction on trade with another nation for punishment or pressure purposes. An act of war involves military conflict. Isolationism is a policy of staying out of foreign affairs. Appeasement is the act of giving in to demands to avoid conflict.

Answer:

B. an embargo