What is the function of Malpighian tubules in a cockroach?

The given figure shows the open circulatory system of a cockroach. Identify the structure that facilitates the flow of haemolymph by its contraction and relaxation.

In cockroach, excretion is brought about by-

$A$. Phallic gland    $B$. Urecose gland    $C$. Nephrocytes    $D$. Fat body     $E$. Collaterial glands

Choose the correct answer from the options given below :

What does '$X$' represent in the given figure?

In the given diagram of the circulatory system of a cockroach,what does $P$ represent?

Match column-$I$ with column-$II$ and choose the correct option.

Column $I$	Column $II$
$A$. Periplaneta americana	$I$. Hepatic caecae
$B$. $A$ ring of $6-8$ blind tubules	$II$. Phylum Arthropoda
$C$. Vascular system	$III$. Spiracles
$D$. $10$ pairs of small holes	$IV$. Malpighian tubules
$E$. Excretion	$V$. Open type