In the Gospel of John, what is the significance of Jesus' statement 'Before Abraham was, I am' (πρὶν Ἀβραὰμ γενέσθαι ἐγὼ εἰμί)?

A It emphasizes Jesus' humility and willingness to serve. B It asserts Jesus' pre-existence and divine identity. C It highlights the importance of Abraham in Jewish history. D It is a metaphorical expression of Jesus' connection to the Old Testament prophets.