Final answer:
Support for temperance grew during World War I due to the need to conserve grain for soldiers and widespread anti-German sentiment that affected German-American breweries. Option B is correct.
Step-by-step explanation:
Support for temperance grew during World War I primarily because of the imperative to conserve grain for the war effort and the wave of anti-German sentiment, which targeted German-American breweries. Option B is the most aligned with historical facts, stating that People believed that grain should be used to feed soldiers rather than to make alcohol.
During the war, there was a strong push to ration supplies, including grain, which is essential for the production of beer and spirits. The idea that valuable resources should not be used for alcohol production when they could support the war effort made temperance and prohibition seem patriotic.
Coupled with this was a moralistic view that consuming alcohol was un-American, especially with the association of alcohol with immigrants, particularly Germans, who were the enemy during WWI.
The temperance movement was further propelled by organizations like the Women's Christian Temperance Union and the Anti-Saloon League, which linked alcohol consumption to societal problems. With the passage of the 18th Amendment, which prohibited the manufacture, sale, and transport of intoxicating liquors, the goal of the temperance movement was realized.
The legislation was supported by the argument that alcohol consumption harmed family life, worker efficiency, and bred social ills. The Volstead Act soon followed, enforcing the amendment and effectively outlawing the consumption of alcohol in the United States.