問英文文法

Sorry for confusion is partly correct, should be

SORRY FOR THE CONFUSION

Because after "for" it should be a noun or noun clause

eg Thank you for your help

("your help" is a noun clause)

Thank you for the present

("the present" is a noun)

3) Sorry for confusion

Definately not the answer '2'.
If you choose '1', you should write in this way:-
"Sorry for being confused"

If you choose '3', you should write in this way:-
"Sorry for any confusion"

Shoud be "Sorry for any confusion"

(I think is)1) Sorry for confused