One of the major tools used to carry out foreign policy is: A. threatening to leave international organizations.
OB. establishing policies that promote isolationism.
C. working with other countries through diplomacy.
D. removing members of Congress who cause problems.

The correct answer is C. Work with other countries through diplomacy.

Explanation

Diplomacy is the name of the science that studies the relations between nations. The objectives of this science are to understand the will for dialogue in international relations, the search for agreements between nations, the use of force, or a military conflict (in cases of confict between countries). According to the above, one of the main tools used to carry out foreign policy is diplomacy, so through this, it is necessary to work with other countries to improve the foreign policy of a nation. Therefore, the correct answer is C. Work with other countries through diplomacy.