Firstly, Congratulations as all of you did the challenge in time. I'm now going to comment on each your photo and afterwards, reveal the challenge winner.
Naomi - This was for me an okay shot. Nothing really wows me, nothing I would not expect. Anyways, the black & white kinda worked out, it gives the theme a different vibe - it gives a more classic/vintage approach. Maybe lower down your chin a bit more and it would have been better.
Kit - I am kind of digging this. Just like what I told Naomi's, the black & white is a different approach, it actually is risky doing this in a city themed shot. You are just working it on this shot, maybe the shoes were kinda distracting, but I get it you are selling to us the shoes, though I was more sold by the coat.
Arthur - While this one is a more obvious approach to a city themed. I like how you just completely blended in on those city type of people, you look formal, you look professional, you look busy. It looks candid but not candid if you know what I mean. I easily can see this in a commercial magazine as well.
Jourdan - And this one looks pretty candid to me as well. Anyways, you are working those legs. It probably made you look taller, however I still am 50-50 about the shot, maybe the lower half was good, but I am not into the upper half of your body. Your hand's on your back pocket is not working.