Question

Which is the most common blood group?

Answer 1

The presence or absence of specific antigens — chemicals that can provoke an immune response if they are foreign to the body – determines blood type. Safe blood transfusions rely on rigorous blood type and cross-matching since some antigens can cause a patient's immune system to attack the transfused blood.

Complete answer:
The presence or absence of two antigens – A and B – on the surface of red blood cells determines the four basic blood types. A protein termed the Rh factor, in addition to the A and B antigens, can be present ($+$) or lacking ($-$), resulting in the eight most frequent blood types $\left( {A + ,{\text{ }}A - ,{\text{ }}B + ,{\text{ }}B - ,{\text{ }}O + ,{\text{ }}O - ,{\text{ }}AB + ,{\text{ }}AB - } \right)$.
The blood group O positive is the most prevalent of the eight blood categories.
Type O is usually in short supply and in high demand by hospitals since it is the most common blood type and type O negative blood is the universal blood type needed for emergency transfusions and immune-compromised infants.
The most common blood type for transfusion is O. As a result, those with AB blood are referred to as universal beneficiaries, whereas those with O blood are referred to as universal donors.

Note:
A blood transfusion is a common medical treatment that involves receiving donated blood through a small tube inserted into a vein in your arm.
This potentially life-saving operation can assist in the replacement of blood lost as a result of surgery or injury. A blood transfusion can also help if an infection inhibits your body from properly producing blood or any of the components of your blood.
The majority of blood transfusions go off without a hitch. If issues do arise, they are usually minor.