It means that that one person or whoever is always there for you and can always count on you. Its that person who you can qualify as a sister or a brother because they mean a lot to you. then it makes you feel not alone in this world cause you have someone to share it with. And make memories good or bad.
A) The city has many other cities and towns under its sway. This is the only answer in which there is nothing to argue about, all other choices you could provide something to contrary of the statement.
