Research on the Theory of Comparative Advantage Involves Which of the Following

Research on the theory of comparative advantage involves which of the following?

A) the study of production and trade and the relationship with government and the distribution of wealth and income
B) the study the relationship between global politics and the global economy
C) the study and method used to examine the relationship between politics and economics across a range of states
D) the study of different countries' factor endowments or technological endowments that allow for the ability to produce particular goods at lower opportunity costs