2

Far right one.

On a side note they all have a look of "I hope they don't shoot us before we can escape ".

3

Right

Left

Third from left to right

Either 1 or 4

One has the weirdest/kinkiest bathing suit, and the sultriest look, 4 looks the most exotic.

2nd

3

4 please. Drain me

None of their belly buttons look right, first off. Far left, especially, and second from left to a lesser extent, have fucked up hands; second from left's left hand and third from left's right hand are also impossibly identical in skin tone, to the extent that they appear conjoined even though depth perception would otherwise suggest that that's impossible. The inside of third from left's left thigh forms a bizarre, unrealistic looking crease for no obvious reason. Far right has what looks like a cameltoe, except that it's barely inside of her left thigh as opposed to being centered on the middle of her crotch. I'm calling it; this is AI. It has to be.

Edit.

Third from left's left hand is partially phased out of existence.

4 is looking at me off frame. ;)