Ascaris is characterized by (a) presence of true coelom but absence of metamerism (b) presence of true coelom and metamerism (metamerisation) (c) absence of true coelom but presence of metamerism (d) presence of neither true coelom nor metamerism.
Option D Ascaris belong to the Phylum Nematoda of Superphylum Aschelminthes. They have a cylindrical body without showing any metamerism, a pseudocoel (false coelom) and a complete digestive tract lined by endodermal epithelium. The cuticle covering the body surface bears minute transverse striations giving a pseudosegmented appearance to the worm.