Answer:
Kaiser Wilhelm's aggressive military build-up and his disregard for attempts at peace, is the correct answer.
Step-by-step explanation:
The triple alliance was formed by Germany, Austria-Hungary and Italy in 1882, and agreed to assist each other in case of attack by either France of Russia. Britain and France were afraid of German Navy, so in 1904 they signed Entente Cordiale to cooperate against the threat of Germany. Russia also joined later. Triple Entente merely stated that it was a moral obligation of the three signatories to help each other.