The correct options are
A All tiers of the government should agree to function together.
B There should be mutual trust in all tiers of the government.
C They all should abide by the rules of power sharing.
To ensure smooth functioning of the federation, the federal government and its units must agree on three key principles. Firstly, all tiers of the government should agree to function together. Secondly, all tiers of government should have mutual trust and agree on the ideals of the constitution. Lastly, they should also trust that they will all abide by the rules of power-sharing.