In the 1920s what did business and industries do that caused the economy to slow down?
a. they hired more workers.
b. they speculated in the stock market.
c. they bought stocks on margin.
d. they overproduced goods.

The correct answer is D.

Apart from the financial crash, the intensity of the Great Depression was reinforced due to the simultaneous overproduction crisis.

In a situation of a demand shortage, there is an unsold part of the production. Such unsold items generate losses for the company. If low demand levels persist, companies will be forced to reduce their production and the amount of inputs, including labor. If employment levels are reduced, demand levels decrease further than before.

i think they would live in caves or natural tunnels

d.summerains, the last one