Which of the following is a correct group?

Trichonympha is a symbiont in the alimentary canal of

Identify the correct terms for the following analogy-based questions:
$(i)$ Porifera : Choanocytes :: Platyhelminthes : ....
$(ii)$ Chondrichthyes : Placoid scales :: Osteichthyes : ....

Which of the following statements is incorrect?

Match the following animals with their respective phyla and arrange them in the correct order as per the given list of animals: Animals: $Leucosolenia$,$Opalina$,$Planaria$,$Wuchereria$. Phyla: $Aschelminthes$,$Protozoa$,$Porifera$,$Platyhelminthes$.

Which one of the following figures shows radial symmetry?