In Earthworm,the effective organ for food digestion is

Identify $X$ and $Y$ from the given figure of the reproductive system of an earthworm:

In the earthworm,the blood flow in the dorsal blood vessel is directed towards..........

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.

The main function of the clitellum is:

Chloragogen cells in earthworms are meant for: