The graphic organizer shows the balance of power created by the alliance system in Europe prior to World War I.

Two boxes evenly balanced on a scale are shown. The left box is labeled Triple Alliance, 1882 with entries Germany, Austria-Hungary, Italy. The right box is labeled Triple Entente with entries Great Britain, France, Russia.

Which factor most affected the balance of power and led to the start of World War I?

Territorial disputes in the Balkans led the Triple Alliance to attack the Triple Entente.
Economic disputes in Europe led the Triple Entente to attack the Triple Alliance.
Ethnic unrest in the Balkans and Ottoman Empire caused conflict between the alliances.
Uprisings in many of the colonized regions of Africa caused conflict between the alliances.