Which of the following led to inflation in the United States in the early 1970s?

Which of the following led to inflation in the United States in the early 1970s?
 
  A) The United States borrowed tremendous amounts of money to balance its budget.
  B) The United States increased its import tariffs, which damaged its trade relations with other nations.
  C) The United States' government comprised corrupt officials who embezzled tremendous amounts of money.
  D) The United States witnessed a swarm of immigrants, which led to the rise in the unemployment rate.
  E) The United States experienced an earthquake, which led to an increase in the price of consumer goods.