To encourage the american people to support the world war i effort, government posters and advertisements used
-pleas from soldiers.
-themes of patriotism.
-images of movie stars.
-images of the president.

The answer is: -themes of patriotism.

During the First World War in America, the government launched campaigns to encourage the purchase of war bonds, develop productivity in manufacturing plants, diminish unfavorable reports, and keep people's spirits up. In that matter, the government appealed for patriotism at the same time it called for civilians in America to work harder at home to support the cause.

-themes of patriotism

Explanation:

While numerous posters touted positive patriotic messages, some tapped dread to rally support for the Allied side and alert against spilling data to spies. "Loose lips sink ships" turned into a famous saying.

Then, realistic pictures portrayed a murderous Adolph Hitler and supremacist symbolism of Japanese individuals with evil, exaggerated features.

the correct answer is:

b) a rich merchant.

to protest slavery i would think it would be a