One very special feature in the earthworm Pheretima is that

Options

(a) fertilisation for eggs occurs inside the body
(b) the typhlosole greatly increases the effective absorption area of the digested food in the intestine
(c) the S- shaped setae embedded in the integument are the defensive weapons used against the enemies
(d) it has a long dorsal tubular heart

Correct Answer:

the typhlosole greatly increases the effective absorption area of the digested food in the intestine

Explanation:

The intestine of an earthworm has a peculiar fold of tissue that forms a pocket in the intestine that is visible when viewing a cross section. This space, which runs almost the whole length of the body dorsally is known as the typhlosole and it serves to increase the surface area of the intestine for absorption