I chose the third option. Probably not, but this is about principle...
This whole charade has had one goal in mind from tbe beginning. Unseating our duly elected president. However the whole thing has been a scam from the get go. Trump made a witty joke during the campaign, and Hillary paid the Russians for a fraudulent dossier (there's your collusion) ; and now we have this never ending three ring circus, that is ruining peoples careers. Too many peoples careers. And they are no closer to finding evidence of a crime that Trump committed today; than they were when they started.
That said, because of the stunning failure of this investigation to show criminal activity by Trump; if you were to fire Mueller now, the Left would go ape shit, convinced that it was a conspiracy. It would only cement in their pea brains that Mueller was just about to drop the hammer.
The best way to handle this situation, is to give Mueller a deadline. You have till such, and such a date to make your case. You'll be wasting no more of the taxpayers time, or money. If left unchecked this debacle will simply carry on until the Dems manage to get a majority in the house, so they can begin Articles of Impeachment (which is what this is all about anyhow) ; or until Trumps term is over. There is also the Lefts hope that they could at the very least drag this out until the next election, and play the "how can you vote for a guy who is under investigation" card. Simple.... Just call it a matter. Right Dems?