Answer: b. protectionism
Protectionism is an economic policy which restricts imports from other countries in order to shield the local producers, businesses and workers from foreign competition. Protectionism can take several forms, such as tariffs on imported goods and import quotas.
Protectionism can also have negative effects, such as reducing trade and raising prices for consumers. It can also hurt producers in both countries (exporting and importing). Protectionism is often believed to have a negative effect on economic growth and general welfare.