Hello,
This is certainly a very ugly spot here and one could easily argue about all options being right.
If CO is a decent player he might be 3betting wider against MP as he folds rarely preflop and postflop so I expect mostly depolarized range.
However, I don't think that 4bet/call is going to be great, as I don't think he is going to go crazy with a hand like TT facing a cold 4bet.
4bet/fold is an option, but then we just turn a hand that has some playability postflop into bluff, so I personally prefer to do this with a hand like AQo, which will be bad for calling.
Call is going to put us in trouble postflop from times to times, but we have position, so I think given the circumstances calling here is best. If we were OOP I would probably go for the 4bet/fold.
Folding looks too weak overall but if you are not aiming for maximum EV then it is an option.
Best,
Plamen