Frankly, pretty sure it's all of them. If you look closely at details, there's a lot of them that don't make sense and have the "meltiness" typical to AI output. See for example one of these hanging loops in the train/tram example - it's especially jarring on the one in the back on the right.
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https://www.pexels.com/photo/empty-subway-train-302428/
This is AI generated?? Or do Photoshop filters count as AI?