The achaemenids fell due to a combination of
a. a weakening army and succession problems
b. growing intolerance of other cultures and internal rebellions
c. attacks from central asia and weak bureaucracy
d. bureaucratic infighting and a discontented population

can you post options so i can ?

polisit can also mean a body of citizens. in modern historiography, polis is normally used to indicate the ancient greek city-states, like classical athens and its contemporaries, and thus is often translated as "city-state". the body of citizens came to be the most important meaning of the term polis in ancient greece.