I believe the answer is Checks and balances.
Check and balances is created in order to prevent the government from becoming too powerful and transformed into a tyrant.
By giving both Congress and the President the power to limit each other, none of them could fully create Regulations without additional support from the citizens.
Your answer is (4) controlling the supply of oil to raise prices
Hoover did not handle the bonus army march well because Hoover did not attempt to negotiate with the protestors.
he made it to prevent a government branch from having too much power