Blood circulation in earthworm is:

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.

Typhlosole found in $Pheretima$ occurs in

Which of the following cells in an Earthworm are responsible for excreting silicates consumed along with food?

Choose the correct pair regarding the anatomy of an earthworm:

Column-$I$	Column-$II$
$1$. Spermathecae	$a$. $6^{th}$ to $9^{th}$ segments
$2$. Typhlosole	$b$. $1^{st}$ to $3^{rd}$ segments
$3$. Buccal cavity	$c$. $26^{th}$ to $35^{th}$ segments in intestine
$4$. Pharyngeal nephridia	$d$. $4^{th}$ to $6^{th}$ segment

Match the regions of the earthworm based on the clitellum:
$P$ - Segments $14$ to $16$
$Q$ - Segment $17$ to the last segment
$R$ - Segments $1$ to $13$
Identify the correct sequence for the Pre-clitellar region,Post-clitellar region,and Clitellar region,respectively.