What Order of Events Led to the Real Shock in Banking

What order of events led to the real shock in banking that occurred during the Great Depression?

A) A reduction in the productivity of financial institutions led to a decrease in money supply that led to bank failures that led to a reduction in aggregate demand.
B) Bank failures led to a decrease in money supply, which led to a reduction in the productivity of financial institutions that resulted in the fall of aggregate demanB.
C) A fall in money supply led to a reduction in aggregate demand that caused bank failures and led to a reduction in the productivity of financial institutions.
D) None of the answers is correct.