Why Did Norman Angell, in a Famous Book Written Before

Why did Norman Angell, in a famous book written before World War I, argue that war is a "great illusion"?

A) All people share the same core values, and therefore, they should not fight.
B) A conspiracy of world leaders is responsible for creating wars for their own profit.
C) The costs of war include cutting off lucrative commercial and financial ties, making the costs of war higher than any benefits that might be gained.
D) War is a product of imperial competition, which is the "last stage of capitalism."