According to the Ricardian Model,the Source of Comparative Advantage Is

According to the Ricardian model,the source of comparative advantage is:

A) differences in labor productivity in the different countries.
B) differences in foreign trade policies followed by the governments of the various countries.
C) differences in resource endowments of the economies.
D) differences in the fields of research and development in the countries.
E) differences in the taste and preferences of the consumers in the different countries.