The answer is the first one, “rights which belong to everyone”. The word unalienable means “unable to be taken away from or given away by the possessor”. Which is almost an identical definition as that answer. It’s not “rights which belong to everyone”, because Thomas Jefferson had slaves, it’s not “rights which are secondary to a nation’s security, because if something is inalienable it can not be secondary to anything, and it’s not “right which people endured much hardship to obtain” because the idea of unalienable rights is that you have them intrinsically.