Which of the following statements is correct regarding the composition of blood and lymph?

Which of the following is correct regarding blood coagulation?
$I$. Vitamin-$K$ is necessary for the formation of prothrombin.
$II$. Conversion of fibrinogen to fibrin is done by thrombin.
$III$. Conversion of prothrombin to thrombin is done by the enzyme complex prothrombinase.
The option with the correct combination is:

Which of the following are the pulse points of the lower limb?
$I$. Brachial $\quad$ $II$. Radial
$III$. Posterior tibial $\quad$ $IV$. Dorsalis pedis
$V$. Femoral $\quad$ $VI$. Popliteal
Select the correct option.

$A$: $A$ portal system consists of veins that start from capillaries and end into capillaries.
$R$: All vertebrates have a hepatic portal system.

The state of equilibrium in the body with respect to various functions and to the chemical composition of fluids and tissues is called

Which of the following organs is known as the blood bank of the body?