Type of bend under water closet under slab

You can use:

Medium 90
Long 90
and closet bend.

Sometimes it's nice to use a 4x3 closet bend with a 4" flange if you need some leeway on your measurements. I remember plumbing for bathroom stalls for a church, and needing the exact measurements for centering between the stalls, not know exactly where the framers were going to place their walls. The head framer casually mentioned that the starting wall was going to be moved, and I stopped him. No, you're not changing the plans on me at this point.

When I was doing new construction homes, it was always a 3" medium 90.