It actually doesnt matter if there is a person on the other end of that line. I have forgotten many of these over the years. My go to was always, like oh I always put a random name or phrase or just mash the keyboard. They always ended up prompting me and I would give a few guesses, and if there is any way of them bypassing it, they would do it at that point. The only way to solve this is for them to not to have a way to bypass it.