Richard Bitner described borrowers in the U. S. subprime mortgage crisis as "a messy credit profile, meager incomes, sometimes no time at work, no history of renting a house, and no savings to support a living. " It is not feasible, and government supervision is ineffective. But why are there so many poor people or such a large number of vulnerable groups in American society? What is the gist of the above text? ['The growing income gap is an important cause of the U. S. subprime crisis.', 'The financial crisis in the United States was caused by the subprime crisis of banks.', 'The root cause of the U. S. subprime crisis is that banks lend money to a large number of poor people who are unable to repay their loans.', "U. S. government insufficiently monitors borrowers' ability to repay loans."]