Answer:
The correct answer is B. They have fewer barriers to trade than they do with other countries.
Explanation:
B is the correct answer because in the trade bloc unions countries are able to trade with lower taxes, without physical boundaries. For example European Union is also trade union, which allows people and goods to be transport without any type of boundaries.
A is wrong because being in a trade union doesn't give you the right to use the natural resources of other countries. It only allows you to easier trade with them.
C is also wrong because in this case they not to rely a lot to the countries that are in that bloc.
D is partially correct, but it also depends on how wide and strong the bloc is.
