Are you willing to relocate?
It's a tricky question. If you answer it wrongly then you might be eliminated from consideration even if you're the best candidate in the mix.
Why do employers care where you live? They know you will not make a long commute for very long before you take another job.
If you have to spend an hour, or more, commuting one way to work each day the chances of you staying in that job are far less than someone who lives much closer. Most candidates will leave as soon as they have a viable alternative that allows them to spend more time enjoying their lives.
Many executives will make the long commute work for them. They either get an apartment in the place where the company is located or claim the address of a friend or family member who lives nearby.
Relocation is a negotiation item. If you get drawn into the details of the conversation too soon then you put the cart before the horse. But, if they are firmly sold on you then there can be some give and take at the negotiating table. If you are truly prepared to make the commute work, assure them early on there will be no problems without mentioning the commute, yet.
When it's time for the offer, it's time to negotiate the details of location.