Alimentary canal is absent in

Which one is the excretory organ in the $Platyhelminthes$?

In which of the following is a digestive system absent?

What is the excretory system in flatworms $(Platyhelminthes)$ composed of?

During its life cycle,$Fasciola$ $hepatica$ $(Liver$ $Fluke)$ infects its intermediate host and primary host at the following larval stages respectively:

Which of the following is an acoelomate animal with a protandrous nature?