Counting unique entries only once & 3rd layer of dependent choices

Hello Excelforum,

Attached spreadsheet Trucking Consolidation.xlsm

I actually have two questions this time. Firstly, if you would kindly take a look a the Validation sheet, you would see that under column B (unique cities), there are two instances of both Compton and Los Angeles. I was just wondering how I can make it so that it displays only one of each unique value like in column A (unique states) so that it doesn't defeat the purpose of the list. I don't know how the formulae actually work so some insight would be greatly appreciated.

Secondly, as you can see in the Query worksheet, I have three comboboxes, one for each of State, City, and Company Name. As I already have City being dependent on State, I would also like to make Company Name dependent on City. Once again, I don't know how these formulae actually work so I can't really expand on them myself.

Edit: Nevermind, I figured some of the stuff out with a different approach so this won't be necessary anymore.