After World War I, a. The economy crashed because so many died in the war
b. The economy crashed because the railroads failed.
c. The economy boomed

After World War I,

B. The economy crashed because the railroads failed.

Explanation:

Why the railroads were so important-

The railroad industry was the largest employer outside agriculture in the US and involved large amounts of money and risk.

A large infusion of cash from speculators caused spectacular growth in the industry and in teh construction of docks, factories, and ancillary facilities.

i think it would be cleaveland browns

river is shown in this type of map