What is the purpose of a "coup d'etat

To overthrow a government in order to install a new one.

So the government doesn't continue taking things too far.

Explanation:

a coup d'etat is the removal of a government when the government does something so bad that the people are forced to take action, thing about the horrible things the french government was doing before the revolution.  

the revolution instituted a short-lived roman republic.

answer; /// i believe that the correct answer is (d)the huang he river valley;