Answer: B. Encourage a country to change a policy.
Step-by-step explanation:
An embargo is a restriction on the trade and other commercial activities such as bank transfers with another country. This is done to put the country through some sort of economic hardship that would force it to change a policy.
Recent embargos include the US embargoes against Iran and North Korea for their nuclear activities. Embargoes are also in place against Venezuela for its state corruption as well as actions aimed at undermining the electoral institutions of the country.