Answer:
D. demobilization
Explanation:
Guess what? I got it correct on the quiz. And you know what else? You should too. Demobilization is the period after an armed conflict when soldiers are sent home and industries reduce or halt their production of war materials.
"Labor unrest came to a head in 1919 when workers began to protest in response to the difficulties caused by demobilization. About 4,000,000 workers—one-fifth of the country's work force—went on strike for the right to belong to unions that could bargain collectively."
According to this text (from the lesson), demobilization was the factor that caused various cities to conduct strikes in 1919.
