Tariff makes the most sense. Embargo is a ban on goods or a country, subsidy is money granted from the government to a business and has nothing to do with trade, quota is a limited amount of a product and again doesn't really have anything to do with trade.
Answer:
Political uncertainty.
Explanation:
Political uncertainty is characterized as the potential threat to alter the executive power either through constitutional means or through unconstitutional methods. A high risk of executive breakdown results in slower growth and, likewise, that slow growth, increases the potential for a change in government. The likelihood of a change of government means uncertain future policies that are marked by economic downfall, social unrest, war, revolution, death of political leaders, etc.
