What motivates countries to join regional trade blocs?

removing barriers to trade protects from influence of foreign markets

increasing tariffs adds to the national GDP

eliminating barriers to trade benefits the economies of member nations

expanding trade relationships reduces cultural diffusion

1) - removing barriers to trade does not protect from foreign influence - false.

2) regional trade blocks are usually correlated with decreasing, not increasing tariffs - false.

3) this it true - and this is the reason - correct answer

4) it increased, not reduces diffusion - not the correct answer