Question

"hague peace conference fails to bring about arms reduction"—1907 "german gunboat threatens french holdings in morocco"—1911 "german and british naval buildup increases tension"—1912 which cause of world war i can best be supported using all of these headlines as evidence

Answer 1

Militarism--militarism was one of the causes to World War I which was the build up of military to protect colonies. 

All of the headlines above have the common theme of arms or weapons concerns. The mention of talks to reduce arms and concerns over increasingly weapon development and navy forces all fall under the cause of militarism.