One thing was that Seas were sometimes difficult to navigate which limited communication - D. this was already a factor which limited the possibility of one united Greece emergin because it made it very difficult to talk to these isolated islands that couldbe found through the difficult-to-navigate seas.
Another thing was that C - some city-states were located on isolated islands.
Such as in the case of Tsarist Russia in the earliest 20th century, absolute power can lead to much cynicism towards the autocratic leader, in which he/she is seen as the centre of blame for all social, political, and economic circumstances. this can lead to uprisings, strikes and revolutions where the masses rise up against their sole leader
