What is the function of the typhlosole in an earthworm?

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

In earthworm,the dorsal wall of the intestine from the $26^{th}$ segment to $95^{th}$ segment forms a median internal fold called

Answer the following:
How many types of nephridia are found in earthworm based on their location?

Assertion : Typhlosole increases the effective area of absorption in the intestine.
Reason : Typhlosole,present in the intestine,is the characteristic feature of cockroach.

Explain the digestive tract of an earthworm with a diagram.