Miss/Mrs./Ms.

[Joe Republic]

Option 2 for me.

First of all it is politically correct.

You consider that to be a positive thing?

Secondly, it is simpler to address all women the same way because sometimes marital status may be unknown.

So?  That's the kind of easy mistake that can be just as easily rectified within seconds.  Plus, I hate to think what kind of woman would actually be offended if somebody accidentally got their title mixed up.