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

The correct answer is: "eliminating barriers to trade benefits the economies of member nations".

Regional trade blocks are intergovernment treaties through which several countries agree to eliminate trade barriers among its members, so that they can enjoy free trade within the region. Moreover, they establish a joint external trade policy, setting tariffs and other trade barriers to cope with competitors from outside the block.