Which of the following led to the Great War?

So the Great War (World War One) was a war that started in 1914 and finish on November 11, 1918. It lasted for four years.

Now the start of the war:

began in 1914 after the assassination of Archduke Franz Ferdinand of Austria. His murder catapulted into a war across Europe 

The U.S. didn't go into war for about 2 and an a half years, During the conflict, Germany, Austria-Hungary, Bulgaria and the Ottoman Empire (the Central Powers) fought against Great Britain, France, Russia, Italy, Romania, Japan and the United States (the Allied Powers).

By the time the war was over and the Allied Powers claimed victory, more than 16 million people—soldiers and civilians alike—were dead.

answer placeholder because the system is messed up

the hollywood film industry of 1950 was threatened on several different fronts. television broadcasting was rapidly becoming the dominant entertainment medium in the united states. the paramount anti-trust consent decree requiring separate ownership for production companies and theater chains had gone into effect on 1 january 1950. large numbers of young men and women were marrying, having children, and moving to the suburbs, which affected the viability of downtown first-run movie theaters. foreign revenues were endangered by protectionist tactics including quota systems, high taxes, and blocked funds. finally, the morality and patriotism of hollywood films and filmmakers were under attack from government, religious, and citizens' groups.

explanation: