What did the washington Naval Conference, the Nine-Power Treaty, and the Kellogg-Briand Pact have in common?
A. They were attempts at promoting world peace without the League of Nations
B. They created secret alliances between the former Allied and Central Powers
C. They were a series of naval disarmament treaties involving the Allied Powers of World War I
D. They were disarmament treaties that limited the number of tanks, use of poison gas, and airplanes.

The Washington Naval Conference, the Nine-power Treaty and the Kellogg-Brian Pact have in common the following: they were attempts at promoting world peace without the League of Nations.

The Washington Arms Conference, better known as the Washington Naval Conference, was a series of conferences held at Memorial Continental Hall in Washington D.C. United States President Harvey invited nine nations to these conferences held from 1921 to 1922, without the League of Nations. The countries that participated were Great Britain, China, France, Japan, Netherlands, Portugal, and Belgium.

The conference’s topic was the arms control in the world. The result of the conferences were three treaties: the Four-power Treaty, the Five-power Treaty, and the Nine-power Treaty. The Kellog-Brian Pact of 1928 was an agreement signed by France, Germany, and the United States that was aimed at not using war as a method to resolve differences.