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.
Shell shock is basically PTSD and it was thought to be caused by soldiers being exposed to explodeing shells
I think Memphis, I may be wrong.
