a) Nikon AF-P DX 10-20mm f/4.5-5.6G...

Small, light, inexpensive. Somewhat plasicky and AF-P lenses aren't compatible with all Nikon cameras, but are fine with a D3500. Surprisingly good image quality. Slow f/4.5-5.6 aperture. But it has VR (image stabilization). Get this lens and go have fun using it!

b) Nikon AF-S DX 10-24mm f/3.5-4.5G

A good lens, but ridiculously expensive and not really any better than some much less expensive options.

c) Tamron 10-24mm f/3.5-4.5 Di II VC HLD

Not very familiar with it other than on paper. The earlier version (without VC image stabilization) image quality didn't impress me very much.

d) Sigma 8-16mm F4.5-5.6 DC HSM AF

The widest non-fisheye lens available. Heavy wide angle distortions. Protruding front element makes it impossible to fit standard filters. Pretty expensive, but it goes wider than any other lens, aside from a fisheye.

e) Tokina AT-X PRO DX-II 11-16mm f/2.8

Yeah, it's pretty sharp. But the Nikon AF-P 10-20mm is just as sharp. This Tokina was the sharpest ultrawide in it's day, but that was a few years ago. And, unfortunately, it's also very prone to flare issues. The first version in Nikon F-mount is motorless, so would not be able to autofocus on D3500... but this II is fine in that respect. Quite well made, but uses Tokina's somewhat odd "focus clutch" mechanism to shift from manual focus to auto focus. Fairly large and heavy, super narrow range of focal lengths.. those are the trade-offs to get f/2.8! (See below.)

f) Tokina AT-X 11-20mm f/2.8 PRO DX

Updated version of "e)", has largely solved the flare and limited focal length range issues. Also only one version, which has a built-in focusing motor so is able to AF on all Nikon cameras. But now it's bigger and heavier... 82mm filters (all the others above use 77mm, except the 8-16mm which can't use standard filters and the Nikkor AF-P 10-20mm which uses 67mm).

Do you really "need" f/2.8 on an ultrawide? If you're shooting landscapes and architecture and other sedentary subjects, very probably not. In fact, you will very likely typically be stopping down to a middle or smaller aperture for greater depth of field, not using f/2.8 much or at all. If you are out shooting astrophotography or aurora borealis at night, the f/2.8 might make for a helpfully brighter viewfinder. Sports shooters and photojournalists also may need f/2.8. But landscape shooters probably don't. For a lens to have a larger aperture means other limitations... larger size and greater weight, less focal length range in a zoom, higher price. And often there's some compromise in image quality, especially at the largest apertures.... Possibly less sharpness in the corners and edges of images and/or more chromatic aberration. It's not uncommon for "slower" ultrawide lenses to be better corrected and sharper from corner to corner. Do a lot of careful study and comparison... and ask yourself if you really "need" f/2.8 for what you'll be shooting (a tripod may be a better choice)!

I rolled the dice and got into an EBAY auction on a used Tokina 11-16, "like new" condition, from a 100%-positive seller. I won for $280 +$20 S&H. I think I was able to win at a fairly decent price because 2 other auctions for Tokina 11-16's ended at nearly the same time.

I probably should have saved money by going for the Nikon 10-20 which would have been plenty good enough for a duffer like myself, but the Tokina's f2.8 at all focal lengths sucked me in. I'm guessing that lens will stay in my kit for a year at most. It is likely to end up with my granddaughter in due time -- she is greatly beloved & is a much better photographer than I am.

Thanks to all for your excellent comments & suggestions.