what are the other 2 reasons, i mean i know them but it says its wrong and this one is correct, so i ask, what are the other 2
The bars don't have the same width.
The bars don't start (and end) at equally-spaced intervals.
I'm not sure about you, but MY science and math teachers always tell us to write down a title. Not sure if it says "cities" below the cities. Those are potential mistakes based on how your teachers teach you.