To Test the Gravity Equation of Trade, a Regression Model

Multiple Choice

To test the gravity equation of trade, a regression model was
Calculated for two nations, the United States and Canada,
Testing the correlation among:

A) regional trade, size of GDP, and distance for states and provinces.
B) intra­industry trade, size of GDP, and size of states and provinces.
C) bilateral trade and ratio of GDP for states and provinces.
D) bilateral trade, size of GDP, and distance for states and provinces.