Answer : 1. "Switzerland"
Explanation :

The San Francisco Conference, held in 1945, was where the United Nations (UN) Charter was negotiated and signed. President Harry S. Truman of the United States gave the inaugural address at this conference, emphasizing the importance of establishing an international organization to promote peace and cooperation after the end of World War II. The UN was subsequently founded, and its charter came into effect on October 24, 1945.