Universal donors have no antigens on $RBC$s and have both $a$ and $b$ antibodies. They belong to blood group:

Which one of the following in blood absorbs oxygen?

Give information about $Rh$ blood group.

Blood clotting is primarily caused by which of the following?

Blood examination of an anemic person reveals large,immature,nucleated erythrocytes without hemoglobin. Which of the following,if added to their diet,would alleviate the symptoms?

$A$ patient has type $A$ blood and needs a blood transfusion. Type $A$ blood is not available. Which of the following blood types could be substituted without causing harm to the patient?