After seeing the results of this question's answer 1 is incorrect. From the instruction I believe that either 2 or 4 are the correct answer.
Answer:
They could have decreased protectionism. Protectionism means that they limited free trade between nations and restricted trade of foreign goods. Protectionism is widely accepted as maybe the biggest reason for the development of the Great Depression and thus if the US had decreased it, it most likely would not have happened at all.
Combining the other factors of production in a unique way to make a profit, that's an entrepreneur. :)
