Which of the Following Contributed to the Nation's Economic Crisis

Which of the following contributed to the nation's economic crisis that began in 2007?

A) The influence-peddling scheme of the "Keating five" which led to a housing "bubble."
B) The deregulation of financial institutions, which allowed them to engage in risky practices such as "subprime" mortgages.
C) The collapse of hundreds of savings and loan institutions, which had a ripple effect throughout the American economic system.
D) The overregulation of Wall Street, which began in the Clinton administration, eventually paralyzed credit markets.