Match the following columns:

Column-$I$ (Blood Group)	Column-$II$ (Antibodies)
$P$. $A$	$I$. Absent
$Q$. $B$	$II$. $a$ (anti-$B$)
$R$. $AB$	$III$. $b$ (anti-$A$)
$S$. $O$	$IV$. $a, b$ (anti-$A$ and anti-$B$)

The most popularly known blood grouping is the $ABO$ grouping. It is named $ABO$ and not $ABC$, because "$O$" in it refers to having

On what is the $ABO$ blood grouping based?

Study the diagram given below and identify the cells labelled as $A$, $B$, $C$ and $D$, and choose the correct option.

Select the incorrect statements with reference to $Rh$ grouping.
$A$. Erythroblastosis foetalis is a condition observed having foetus with $Rh^{+ve}$ blood and mother with $Rh^{+ve}$ blood.
$B$. $Rh$ antigen is observed on $RBCs$ in the majority of human beings.
$C$. Before blood transfusion,$Rh$ group should also be matched.
$D$. $Rh$ incompatibility is observed when a pregnant mother is $Rh^{-ve}$ and the foetus is $Rh^{+ve}$.
$E$. Erythroblastosis foetalis can be avoided by administering anti-$Rh$ antibodies to the mother immediately after the delivery of the second child.
Choose the answer from the options given below:

Erythropoiesis starts in