Economist: Some people argue that when large countries split into several small countries, the world economy is harmed by increased barriers to free trade in the form of an increased number of national tariffs.
Your task
Find the assumption that, if added, guarantees the conclusion follows.
Common trap
Answers that only partly bridge the gap, leaving the conclusion unproven.
Winning move
Identify the new term in the conclusion and pick the choice that links it to the evidence.