What event is widely considered to have started World War I?

Which group was Gavrilo Princip, the assassin of Franz Ferdinand, a member of?

Which country issued an ultimatum to Serbia almost a month after the assassination of Franz Ferdinand?

Which country gave a 'blank check' promise to Austria to help if Russia mobilized?

Which major power declared war first in the sequence of events leading to World War I?

Which country declared war on France on August 3, 1914, in the sequence of events leading to World War I?

What kind of event started a war in the Korean conflict?

Which major power was surprised by Austria's sudden declaration of war on Serbia on July 28, 1914?

What country issued an ultimatum to Germany to withdraw from Belgium, leading to war declaration by Britain?

What was Gavrilo Princip's nationality?