Final answer:
A trade barrier that adds a special tax on imported goods is called A. tariff. It protects domestic industries but can increase prices for consumers.
Step-by-step explanation:
The type of trade barrier that involves adding a special tax on goods brought into a country is known as a tariff. Tariffs are used by governments as a tool for protectionism, which raises the price of imported goods, thus making domestically produced goods more competitive in the local market. This action has the effect of encouraging domestic production and potentially safeguarding local jobs, but it can also lead to higher prices for consumers and reduced selection of goods.