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.
Piracy--the attack of piracy was the attacking of ships and taking of the goods.
Pirate or privateers worked in crews with a hierarchy targeting merchant ships to attack and take the good on the ship. The goods would then be sold on the black market or traded for other more valuable items. Royal ships were especially targeted as they often contained gold and other luxury items.
Julius Caesar did indeed commit treason by crossing the Rubicon because it was legally proscribed that if any army-leading general crossed the boundary it would start a coup d'etat which was strictly forbidden. Because of the crossing, it started the Roman Civil War.
The correct answer is B. Laws would be established by majority rule.