Setae are present in all body segments of the earthworm except in the ..........

Nephridia of $Pheretima$ are

Which one of the following correctly describes the location of some body parts in the earthworm $Pheretima$?

Identify the incorrect statements among the following:
$(a)$ In earthworm,a single male genital pore is present.
$(b)$ Setae help in locomotion of earthworm.
$(c)$ The muscular layer in the body wall of earthworm is made up of only circular muscles.
$(d)$ Typhlosole is a part of the intestine of earthworm.

In $Pheretima$,nephridia occur in:

Earthworm possesses how many pairs of hearts?