In the 1950s the house of un-american activities committee blacklisted 320 people who are associated with-

They were associated with the entertainment industry.

it increased the power of the king of england.

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.