The leader of the Athenian Empire worked to a.) give citizens direct input into the government.
b.) create a dictatorship within the city-state.
c.) withdraw from the surrounding territories.
d.) bring together the city’s elected officials.

a.) give citizens direct input into the government.

1. The judicial review checks if the law passed by the congress is constitutional. This limits the power of the congress without it and it would have unlimited power, and could for example re-introduce slavery. The congress won't do it, because they know that the law would be deemed unconstitutional. 

2.  The president is foremost a Chief of State - that also means the Head of State. This means that the president represents the US, for example during the meeting of the Heads of State. 

3. The US Civil Service is the workforce of people working for the Government in non-military positions.They are employed, and not elected, so they don't have terms. Those positions include administrative positions in the government. 

4.The Cabinet is the Council of the heads of the departments which is the body that the President works with most directly, and it advises the president on their relevant areas of expertise.