The correct answer is B) to provide protection from its enemies.
Increasing militarism led European powers to form alliances to provide protection from its enemies.
European nations were not sure to really had the capacity to defend themselves alone with the increasing of militarism and the weaponry of the time. They knew that alone, it could be more difficult to defend in case of military aggression.
That is why they formed alliances such as the Triple Entente in 1912: France, Great Britain, and Russia. Or the Triple Alliance: Germany, Italy, and Austria-Hungary, in 1882.
