The correct answer is (b). The Paris Peace Conference was a series of international meetings held in Paris, France, from January 18 to June 28, 1919. The conference was called to discuss the peace terms that would be imposed on Germany and its allies after World War I. The conference was attended by representatives of 27 Allied nations, including the United States, France, Great Britain, Italy, and Japan. The conference resulted in the signing of the Treaty of Versailles, which officially ended World War I.
The other options are incorrect. London was the site of the London Naval Conference of 1930, which was a conference of naval disarmament. Vienna was the site of the Congress of Vienna, which was a conference of European powers that met to redraw the map of Europe after the Napoleonic Wars. Washington was the site of the Washington Naval Conference of 1921-1922, which was a conference of naval disarmament.