Consider the Sources of the Gains from International Trade

Consider the sources of the gains from international trade.Governments often implement programs designed to encourage research and development.Such programs may change the comparative advantage of that country because

A) they are expected to change the endowments of each country.
B) they are expected to lead to improvements in technology.
C) they will raise the costs of production of the trading partners.
D) the opportunity costs of exported products cannot change.
E) increases in research and development always lead to an increase in imports.