Which of the following is the casting-off of the outer dead rigid covering of an animal body during its growth?

Ecdysis is the moulting of the cuticle in many invertebrates. Moulting is the defining feature of Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, tardigrades and Cephalorhyncha. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed.