How do you know that this collection of books is correct?
Catholics claim the authority of Christ's Church. Where does your authority come from?
My authority comes from the triune God.
I don't. This is the only Bible that I have that contains the Apocrypha.
For a time during the seventeenth century, it was illegal to print a Bible without the Apocrypha, but for centuries, Protestants have disagreed as to whether it belonged in the Bible. Today, most Protestant Bibles exclude these writings.