How did World War I affect the film industry?

The impact of World War I on the film industry was profound, particularly in how it catalyzed an increase in film production and the creation of propaganda films. As the war unfolded, governments turned to film as a powerful medium for influencing public opinion and boosting morale. This led to the production of numerous propaganda films that aimed to rally support for the war effort, educate citizens about wartime realities, and promote nationalistic sentiments.

Moreover, the urgency and significance of the war created a demand for films that depicted military actions, heroism, and the emotional struggles of both soldiers and civilians. As a result, studios expanded their output to meet this increasing demand, resulting in a notable surge in film production during this period. This increase was not only in quantity but also in thematic content, as filmmakers began to explore deeper social issues related to the impact of war on society.

The other options do not capture the complexity of the film industry's transformation during this era. While film production did see fluctuations during the war, the crux of the effect was the mobilization of the industry for propaganda and the associated increase in content production.