The following statements describe the meaning of International trade, Terms of trade, Balance of trade and visible exports. Type in the one that suits best the description.

Description Type of Trade
a) Ratio at which a country's exports exchange with its imports.
b) The difference between the value of visible exports and imports over a long period of time.
c) Exchange of goods and services between two or more countries.
d) Physical or tangible goods a country sells to other countries