Answer :
It would have to be C. For answer A, people going into debt while not being able to pay back te money caused bank failures (Credit). B looks like the same as A, risky loans made by banks to people who are unable to pay them off. Answer C is incorrect because MANY people were not aware of the stok market crash and asked their broker to hand them money. When the broker issued a frantic margin call, other brokers started calling and pretty much everyone had to sell at the same time, which issued the crisis. D is correct and is still happening today.