Answer:
B. Ecdysozoa.
Step-by-step explanation:
Ecdysozoa is the large group of animals that undergo the process of ecdysis which can regularly shed their outer skin made of the cuticle. This process of shedding the outer skin is also known as molting which is observed in the species of the nematodes and the arthropods.
In the given question, since the new species shed their outer skin which is a characteristic feature of the Ecdysozoa, therefore, the new animal species belongs to the Ecdysozoa.
Thus, Option-B is the correct answer.