"The equilibrium relative commodity price at which trade takes place is determined by the conditions of demand and supply for each commodity in both nations. Other things being equal, the nation with the more intense demand for the other nation's exported good will gain less from trade than the nation with the less intense demand." This statement was first proposed by:
选项：

A:Alfred Marshall with offer curve analysis
B:John Stuart Mill with the theory of reciprocal demand
C:Adam Smith with the theory of absolute advantage
D:David Ricardo with the theory of comparative advantage