What 3 factors played a role in economic prosperity experience in america following world war one

Before WWI America owed Europe a lot of money, but after WWI the situation changed and the former allies owed America more than US$ 10 Billion for the cost of armaments and food supplies.

The payment of these debt by the allies allowed the US to use this money to increase the insdustrial factories .

After the WWI a decade of tremendous prosperity started. This economic boom was a consequence of the mass production industries increasing gross domestic products, productivity and income, so business sales increase, driving up profits.  

i believe 5 is correct answer