How did countries use propoganda to support the war effort?

(38 points, Brainliest)

As well as attempts to influence public opinion in neutral countries/areas, propaganda was used directly at enemies. From the beginning of the war, airplanes were used from all sides of the war to drop posters over fighting armies and civilians/people.  World War I was the very first war in which mass media and propaganda congregated and played an important and beneficial role in keeping the apprehensive people sheltered at home informed about what was happening on the battlefields.  It was also the first war in which the government methodically created propaganda as a stratagem to target the public and change their opinions.

Explanation:

c, they united with once