67. Many people in the U.S. who financed house purchases by SUBPRIME MORTGAGES during 2000-2006 ran into serious default troubles in 2007 due to .: all of the above.,the sharp rise in interest rates engineered by the Fed Chairman (Greenspan) over 2004- 2006.,the sharp widespread drop in U.S. housing prices starting around 2006.,Only A and B.,the fact that many of these subprime mortgages were in the form of adjustable rate mortgages (ARMs) which permit lenders to increase borrower interest payments in response to increased market interest rates