Likely depends on some factors. Actually oddly enough stink bombs would work pretty well. Leonhardt would personally suggest smoke canisters since those give the appearance of a fire and that sure gets people out fast.

Another idea could be to try and combine B and C. Put up a distraction as a front to kidnap the bureaucrat. Has the advantage of removing witnesses for sure and makes it easier to move around, plus in the chaos people are less likely to notice someone moving to kidnap someone.

And as far as option C goes, as much as Leonhardt hates admitting to it, he does have experience kidnapping people.