Final answer:
An embargo is a trade barrier implemented by a nation to prohibit the importation of goods, such as fruit, and is a form of protectionism.
Step-by-step explanation:
A nation that passes a law prohibiting the importation of fruit is implementing a trade barrier known as an embargo. This is a type of non-tariff barrier, which is one of the tools governments use to practice protectionism. Protectionist policies like tariffs, import quotas, and non-tariff barriers are designed to restrict foreign competition and protect domestic industries. While these trade barriers can benefit domestic producers by reducing competition, they often lead to higher prices for consumers.