There isn't really any acceptable choice between the four listed.
Nuclear weapons are simply way too destructive, and national governments way too irrational, for the later to be worth of keeping the former.
Given that nuclear weapons are unavoidable (apparently the technical knowledge necessary to build them isn't all that secret anymore) we would need some sort of international organization with a better system of keeping their use unattractive.
Mutual Assured Destruction doesn't really cut it; it was that doctrine that led to the nuclear arms race, a system that has no mechanisms for slowing down its pace.
Fat chance that I of all people will have a halfway workable solution for that situation, but I will try anyway.
First of all, I think that there is a very strong need for nuclear weapons to be well documented. Any indications of secret nuclear weapons must be kept terribly inconvenient even for the most unbalanced power mongers. Perhaps a mechanism for that could be some sort of heavy, long lasting commercial and diplomatic repercussion on a per-hidden-head basis. Or strong restrictions of access to communications, including banking systems. Or obligatory exchange of a number of citizens with some foreign power not of their choice. The goal is to have some sort of consequences that is so inconvenient and so avoidable by simply refusing to hide nuclear weapons' existence that it won't happen.
What about the well documented, openly extant weapons? Tax the innards out of them. Require a certain number of soldiers for UN peacekeeping forces in exchange for each nuclear head. Above all, spread the numbers and expense bills for their construction and keeping for all that could want to see them. Particularly opposition political parties and separatist movements. If the people have to bleed to build fear, at least have them see the blood flow.
Hopefully that would help in creating the very necessary disgust of any community in realizing that their governments keep nuclear arsenals.