Answer:
B) All vertebrates are chordates.
Step-by-step explanation:
Chordates (Filo Chordata) are all animals that have the notochord, in which they may be permanent or at some point in their life. Every vertebrate is a chord, but not every chord is a vertebrate. As an example of this phrase, we can cite the Protocordates represented by two subphyls: Urochordata (represented by the Ascidians) and Cephalochordata (represented by the amphioxes).
Thus, the inferior protorcordados or chordates are animals that have the notochord, but that do not have the bony skeleton, therefore they are not vertebrates.