90BB effective
Hero in BB with J10o
folds to SB who raises 2.5x.
Hero is getting roughly 2.5 to 1 to call. (Antes)

Do you A) Raise to x B) Call C) Fold
Why?

Thanks in advance!

Anyone who tells you they know the gto answer to this is full of ****.

For BvB situations existing computational solvers can solve this with a decent bet sizing abstraction (and a flop subset abstraction if you want it to be cheap to calculate). I don't think this qualifies as something beyond reasonably sound estimation with current tools. Someone willing to spend a decent amount of money on this specific question could compute a pretty compelling answer.

I haven't ran anything myself at 90bb nor with antes so I don't have an exact answer, but at 100bbs, no ante, and no rake, the game tree I have with a 2bb open raise option and a 3bb open raise option calls the vast majority of the time with a small % of raising with JTo against both a 2x and 3x open. Folding is massively less EV according to the computational solution (about 1.2BBs worse) and I would be shocked if it could be acceptable at any frequency, even given the approximations required to compute the solution.

I'd say call huge % and raise small %, to around 8-9bb. (like 90/10 or 95/5 kind of thing).

Just guessing of course

I would go a step further than this and say that probably anyone who claims they know how many valid GTO answers there are is full of ****.

CALL

you're so fos man

A) 3b because SB folds often enough and you have position. If he doesn't fold often enough, you have a decent hand IP.
B) Call as his range is dominating your range after 3b.
C) Fold if he is open raising tighter than CO or MP.