What Is a Tariff

How have U.S.imports and exports,as a fraction of GDP,changed from 1970 to the present?

Absolute advantage is A) the ability to produce more of a good or service than competitors when using the same amount of resources. B) the ability to produce higher quality goods compared to one's competitors. C) the ability to produce a good or service at a higher opportunity cost than one's competitors. D) the ability to produce more of a good or service than competitors that have more resources.