Which was a major cause of the event reported in the newspaper at the left?

Exhibit:

Which was a major cause of the event reported in the newspaper at the left?
A . the sharp drop in the value of stock
B . the crash of the zeppelin Hindenberg in New Jersey
C . the national debts from World War I
F . businesses lagging in technological developments
G . the government buying all the stock in
. businesses

Answer: A