If I'm an active military reservist, do I select "Active military duty" when uploading W2? I'm not full time active duty; just an active reservist.

Yes, if were you were considered active duty during the year then you will select the "active military duty" for your W-2.

Depending on your state, you might have to enter the amount that was active duty pay during the state interview if not all of it was active duty pay.