Final answer:
Propaganda was used to support the war by manipulating information to foster patriotism and quell dissent, with efforts like the Committee on Public Information during WWI and extensive use of media during WWII. The correct option is D.
Step-by-step explanation:
Propaganda was used to promote support for the war by manipulating information to create a strong sense of nationalism and to suppress any dissent. The Committee on Public Information, for example, produced pro-war propaganda during World War I, using posters and public speeches to portray the enemy in a negative light and to encourage Americans to support the war effort.
Additionally, during World War II, various forms of media such as radios, movies, and newspapers were instrumental in spreading propaganda. Patriotic messages, broadcasts from the front, and even children's cartoons were used to demonize the enemy and promote war efforts. This media influence played a crucial role in uniting the public behind the war cause.