Do you mean during the time in Great Depression? if so, is due to the state of US. It was the largest producer and creditor in the world after WWI. It lent money to Britain and France to help them recover their economies and helped Germany pay its war indemnity. In addition, many other countries depended on the US as a major market for their products. As a result, US played a leading role in the economic development of the world.
Sadly, someone shared a rumour of stock shares that there would soon be a recession. US was in panic and many sold their shares leading to the decrease in economy, which affected every other country, especially European countries and Germany, whom had to pay the indemnity and pay the loan.
I'm pretty sure it's A because on an article it says "There were high amounts of meat including pork" etc. Hopefully I helped with something :)
The answer is b. conquest and diseases brought by Europeans changed the native American way of life forever.
It was the attack on Pearl Harbor
The caning of Charles Sumner highlighted sectional tensions between the North and the South.