Why might the Italian city-states have resisted the exploration around the world

the answer would be logic.

b. native americans them

yes they have. but is this a true false question? if it is, the answer is true.

map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. for example, on a 1: 100000 scale map, 1cm on the map equals 1km on the ground.