Arrange the following events in chronological order:
1) World War I began
2) USA entered the war
3) Italy entered the war
4) Formation of League of Nations
5) Treaty of Versailles
6) End of World War I
A. 1,2,3,5,6,4
B. 1,3,2,6,5,4
C. 1,5,2,3,6,4
D. 1,2,3,5,4,6