4. In an emergency situation, a person with blood type A could receive

type A blood only.

O type o blood only.

o type A or type o blood.

O type A or type AB blood.

In an emergency situation, a person with blood type A could receive type A or type O blood.

Explanation

Blood type A has anti-B antibody in the plasma and O type blood has no antigens. The presence or absence of antigens determine the blood group of individual. The O group is free of antigens and does not trigger an immune reaction in the body and hence are also known as universal donor.