Explanation:
the advantage is that you can get your goods transpired faster.
the disadvantage is that when the trains would pass there would be a lot of noise which would scare your animals.
I'm not entirely sure of this answer.
Oftentimes it is "removing barriers to trade" that motivates countries to join regional trade blocs, since members of such "blocks" have completely free trade with one another. :
The answer is A.) Germany