Question

Which sentence best describes the influence of alliances on the start of World War I?
Alliances delayed the beginning of World War I because nations were afraid to attack one another.
Alliances forced member nations to settle their differences through talks rather than through armed attacks.
Alliances prevented many European countries from joining the war because they had signed a pledge not to.
Alliances between nearly all European nations meant that when two went to war, all became involved.

Answer 1

"Alliances between nearly all European nations meant that when two went to war, all became involved."

Reason: The prewar alliance system turned the Austro-Serbian conflict into a wider European war as Russia, Germany, France, Britain, etc., were drawn in by treaty obligations and mobilizations.