Which blood vessel in $Pheretima$ contains valves?

The chloragogen cells of $Pheretima$ perform a function similar to which organ in vertebrates?

Choose the correct option for the following statements:
$(i)$ Earthworms have $4$ pairs of lateral hearts.
$(ii)$ The excretory organs of earthworms are nephridia.

Which cells or glands in an earthworm provide nutrition to the unfertilized eggs?

The main function of the clitellum is:

In which of the following are the nephridial funnels (nephrostomes) present?