Why were tanks developed during world war 1?
a) to provide shelter from poison gas
b) to carry heavy anti-aircraft guns
c) to protect soldiers when they attacked trenches
d) to be advanced scouts for infantry

C. to protect soldiers when they attacked trenches

no options provided, here,but the answer to this question is often: a historian cites a japanese newspaper article published a year after the end of world war ii in order to draw conclusions about the effect of the war on the japanese economy.

clearly from the answer, the historian alludes to historical sources,and records to aid in analyzing and drawing conclusion on the effect of the war on the economy of japan.