The vertebral column developes from which of the following structures?

Vertebral column developes from notochord which is a mesodermally derived rod-like structure present in the embryonic stage.The members of subphylum Vertebrata possess notochord during the embryonic period. The notochord is replaced by a cartilaginous or bony vertebral column in the adult. Thus all vertebrates are chordates but all chordates are not vertebrates