I voted 'Other'.

For the most part my cats are indoor cats, however most of them are leash trained and I do sometimes take them out for a walk (or in Pooky's case a bike ride or golf cart ride also). They also have a custom built cat enclosure in the back yard hubby and I built that I take the cats out to when it's nice outside. Which is why I had to vote 'Other' rather than 'Indoor'.