Answer:
C. Chordates
Explanation:
Even though the chordates seem to be the most marking of the animal kingdom, they are the ones that are most commonly seen, and they are the largest and most complicated, they are actually a very small minority in the animal kingdom. All of the chordates comprise for only around 5% or even less than all of the species in the animal kingdom. On the other side, the invertebrates make up the rest of the 95% or more of all animal species. The chordates are the animals that have a backbone to put it simple, and some of the members are the mammals, reptilians, birds, fish etc.
