Final answer:
An example of retaliatory trade restrictions is the U.S. response to the EU ban of hormone-treated beef.
Step-by-step explanation:
An example of retaliatory trade restrictions is the U.S. response to the EU ban of hormone-treated beef. When the EU banned hormone-treated beef imported from the U.S., the U.S. responded by imposing tariffs on certain EU products, such as cheese and wine. This action was taken in retaliation for the EU's trade restriction, with the goal of pressuring the EU to reconsider its ban. This is an example of how countries can use trade restrictions as a form of retaliation in response to another country's trade barriers.