Answer:
C) the flow of goods and services.
Step-by-step explanation:
In macroeconomics, the trade balance = exports - imports.
Exports are the goods and services produced domestically in your country that are sold to buyers in other foreign countries.
Imports are the goods and services produced in other foreign countries that are sold to local buyers in your country.
Exports and imports flow between countries, and the trade balance basically shows us if the country imported more foreign goods or exported more domestic good to international markets.
The trade balance is part of the current account of a country.