I think Solution #3 is already underway. There are already some Muslim neighborhoods where even the police refuse to go, and there are virtually no city services there because other city employees are too afraid to enter them. I think you're right on the likelihood of the French simply expanding and making official the establishment of a separate "Muslim zone."
Sadly, I think that even if they were inclined to respond as in your Solution #2, there'd be so much international (read EU and Muslim countries) pressure on them that they wouldn't be able to do it effectively. I've already seen whining in the US press, which is barely covering the incidents, to the effect that it is all the fault of the French for not being nicer to their "immigrant" population.
Some immigrants. Invading army would be more like it, and to make matters worse, the invading army is being funded almost entirely, from cradle to the grave, by the French taxpayer.
The same thing can be said of this country.