Which of the following is found in an earthworm?

Which segments of the earthworm contain the clitellum?

Match the following and select the correct option:

Column-$I$	Column-$II$
$P$. Testes	$I$. $18^{th}$ segment
$Q$. Accessory glands	$II$. $17^{th}$ and $19^{th}$ segments
$R$. Male genital pore	$III$. $6^{th}$ to $9^{th}$ segments
$S$. Spermathecae	$IV$. $13^{th}$ segment
$T$. Ovaries	$V$. $10^{th}$ and $11^{th}$ segments

In an earthworm,which of the following acts as a hydrostatic skeleton?

Following are the statements about the prostomium of an earthworm.
$(a)$ It serves as a covering for the mouth.
$(b)$ It helps to open cracks in the soil into which it can crawl.
$(c)$ It is one of the sensory structures.
$(d)$ It is the first body segment.
Choose the correct answer from the options given below.

How many types of nephridia are there? Mention them.