Which of the following constitutes the correct pairing?

Which of the following is a free-living flatworm?

What is the covering present around the body of parasitic animals belonging to the phyla Platyhelminthes and Nematoda?

In which of the following phyla is sexual dimorphism not observed?

In the life history of the liver fluke,the following stages are present: $(1)$ Cercaria,$(2)$ Metacercaria,$(3)$ Sporocyst,$(4)$ Redia,$(5)$ Miracidium. What is their proper sequence?

An animal without an anus is