Choose the correct option representing the organisms belonging to their respective classes.

Trichonympha is a symbiont in the alimentary canal of

Read the following statements.
$(a)$ Metagenesis is observed in Helminths.
$(b)$ Echinoderms are triploblastic and coelomate animals.
$(c)$ Round worms have organ-system level of body organization.
$(d)$ Comb plates present in ctenophores help in digestion.
$(e)$ Water vascular system is characteristic of Echinoderms.
Choose the correct answer from the options given below.

Which of the following pairs is incorrectly matched?

$P$ - Assertion: Circulatory system is present in Annelids.
$Q$ - Reason: Circulatory system is absent in Aschelminthes.

Which of the following groups are classified as Anamniotes?