I'm guessing these are baby bunnies? They're harder to sex.
First of all, as a disclaimer, I am not a breeder and my experience with sexing is limited. Others may disagree with my opinion here.
From what my old eyes can tell, the first pic looks female. #2 looks female to me (teardrop shape) but the light isn't the best. #3 has the classic female teardrop shape. #4 is a bit blurry, hard to tell. I see the teardrop, but there's what looks like a bit of protrusion as well. If I could see from the side I'd have a better idea. On a male, the penis looks like a little tube with a circular tip that protrudes noticeably. Girls always have a teardrop shape with a slit instead of a round, circular opening, and it's a lot flatter. They look very similar to a female cat.
Usually when I sex them, I roll my fingers around a bit as I'm pressing on the vent, to get a better view of how far the genitals protrude, and I view them from a few angles. I wear a head lamp so that the light is better. You'll notice in the sample pics on the website I posted, they show the males from the side so you can see how far the penis protrudes. Try looking again, paying close attention to how far the genitals protrude and the shape of the opening at the tip. Those are the two things that show it's male: protrusion (like a little tube) and a circular opening - not a slit or a teardrop.