What was the primary problem with mortgagebacked CDOs, which triggered the subprime crisis? Select one: Q a. they were formed by pooling high quality xed-rated loans with low interest rates. O b. they were formed by pooling subprime mortgages O c. mortgage-backed CDOs had nothing to do with the subprime crisis 0 d. the mortgages were variable rate loans C) e. the investment bankers underestimated correlation O f. interest rates increased