Which of the following was not one of the principles on which the general agreement on tariffs and trade (gatt) was established?
a. the elimination of important quotas.
b. equal, nondiscriminatory trade treatment for all member nations.
c. the formation of international trade contracts to alleviate global proverty.
d. the reduction of tariffs by multilateral negotiations.

Option (C) is correct.

Explanation:

Important principle on which GATT was based was trade without discrimination, in which member nation tend to open their markets equally to each other. Therefore this meant that, if a nation and its trading nation had come to conclusion to reduce tariff, this was automatically expanded to every member.  Another principle is in regards with protection via tariffs instead through import quotas or other trade restrictions.

what words? are you talking about to complet what sentence

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."