Read the following statements
A) All vertebrates are chordates but all chordates are not vertebrates.
B) All jawed vertebrates are tetrapods but all vertebrates are not gnathostomes.
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. All vertebrates are chordates but all chordates are not vertebrates.
All jawed vertebrates are not tetrapods. Pisces also belong to gnathostomata.