The correct option is B Cyclostomata
Jawless vertebrates are included in the class Cyclostomata and division Agnatha.
Hemichordates are called as half chordates as they have some characteristics of chordates and lack some.
Chondrichthyes includes cartilaginous fishes which are the first jawed vertebrates. Jawed vertebrates include Pisces, amphibians, reptiles, birds and mammals.