Which segments of the earthworm contain the clitellum?

Answer in one word or one line.
How many spermathecae are found in earthworm?

Match the following columns regarding the types of nephridia in earthworms:

Column-$I$	Column-$II$
$P$. Septal nephridia	$I$. Enteronephric
$Q$. Integumentary nephridia	$II$. Exonephric
$R$. Pharyngeal nephridia

The figure below shows the circulatory system of an earthworm. What are $P, Q$,and $R$?

The body segments in earthworm are called

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.