One Lesson from the Credit Crunch Is That

One lesson from the credit crunch is that

A) in the aggregate, credit scores tend to understate the probability of default-thereby a pool of subprime mortgages is actually quite a safe investment since not every borrower defaults.
B) moral hazard, while an issue in the market for used cars, does not seem to affect the U.S. financial system due to the effective regulatory environment.
C) bankers seem not to scrutinize credit risk as closely when they serve only as mortgage originators and then pass it on to MBS investors rather than hold the paper themselves.
D) none of the above