Explain how buying stocks “on margin” caused black tuesday?

the answer is a, salt plain

depending on what kind of map for example a pltical maps works in many ways this iss how it works it shows the areas and places the democratics and the repbulcicans reside for example if   texas chooses trump for president there a republican state and if   califronia chooses hillary there a democratic state.

i think that the right answer is the aztecs