The nephridia in earthworm are analogous to:

Explanation

Analogous organs are organs of very disparate organisms that are superficially similar but have evolved from vastly different origins. They have the same function but different structures. The nephridia in earthworm are analogous to flame cells of Planaria since both of them have excretory functions. Nematoblasts of Hydra are organs of locomotion, food capture and anchorage. Gills and trachea are organs of respiration in prawn and insects respectively.