[Solved] What kinds of proteins are usually recognized by the cap of a proteasome? A)proteins with a single ubiquitin B)naked proteins C)precipitated proteins D)polyubiquitinated proteins E)lysinated proteins Trade Restriction: Measures implemented by governments to control the amount of trade across borders, including tariffs, quotas, and non-tariff barriers. Production Relationships: The correlations between input factors and the resulting output in the production process of goods or services. Production Possibilities Frontier: A graph showing all the possible highest production levels for two or more products, given certain inputs. Trade: The act of buying, selling, or exchanging goods and services between people, firms, or countries.