Which American wrote A Farewell to Arms and The Sun Also Rises?
Ernest

Ernest Hemingway

Explanation:

Ernest Hemingway wrote The Sun Also Rises (1926) and A Farewell to Arms (1929), which were full of the existential disillusionment of the Lost Generation expatriates; For Whom the Bell Tolls (1940), about the Spanish Civil War; and the Pulitzer Prize-winning The Old Man and the Sea (1952)

secretly cooperate with one another.

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.