Which of these factors helped cause world war 1 A. Rising tensions between Catholic and Protestant nations in Europe
B. The sudden economic depression the left Europe vulnerable to attack
C. Border disputes between fascist and non-fascist countries
D. An alliance system that required allies to aid one another in armed conflicts

The factor that helped cause World War one was an alliance system that required allies to aid one another in armed conflicts.

Explanation:

The conflict was a result of tensions between the European powers along with the crisis of the balance-of-power system that splited Europe into two sides. One the one hand, one side was made up of Great Britain, France and Russia, which was called the Triple Entente. It strove seeking to preserve the weak balance between the European great powers. On the other hand, the German Empire, Austria-Hungary and Italy (Central Powers) formed the other camp.

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i confess that there are several parts of this constitution which i do not at present approve, but i am not sure i shall never approve them: for having lived long, i have experienced many instances of being obliged by better information or fuller consideration, to change opinions even on important subjects, which i once thought right, but found to be otherwise. it is therefore that the older i grow, the more apt i am to doubt my own judgment, and to pay more respect to the judgment of others.

the process is called revolution because it was a process of great economic-social transformations that began in england in the xviii century.

the industrial mode of production spread throughout much of the northern hemisphere throughout the xix and early xx centuries.

the effect of this revolution was the distance between the countries, with respect to economic and political power.   after all, not all industrialized at the same time, remaining in the condition of suppliers of raw materials and agricultural products to the industrialized countries.

these differences mark to this day the nations of the world that are divided between developed and developing countries. one way to measure whether a country is advanced is to assess how industrialized it is.