The correct answer is O-.
Blood type is determined by the presence or absence of certain antigens on the surface of red blood cells. The four main blood types are A, B, AB, and O. People with type A blood have the A antigen on their red blood cells, people with type B blood have the B antigen, people with type AB blood have both the A and B antigens, and people with type O blood have neither the A nor the B antigen.
In addition to the A and B antigens, there is also an Rh factor, which can be either positive or negative. People with the Rh factor are Rh-positive, and people without the Rh factor are Rh-negative.
When a person receives a blood transfusion, it is important that the blood type of the donor is compatible with the blood type of the recipient. If the blood types are not compatible, the recipient’s immune system will attack the donor’s blood cells, which can lead to serious complications or even death.
O- blood is the universal donor blood type. This means that O- blood can be safely given to people with any blood type. This is because O- blood does not have any antigens on the surface of the red blood cells, so it is not rejected by the immune system.
AB+ blood is the universal recipient blood type. This means that people with AB+ blood can receive blood from any blood type. This is because AB+ blood has both the A and B antigens, as well as the Rh factor.
A- blood can only be given to people with type A or type AB blood. B- blood can only be given to people with type B or type AB blood. AB- blood can only be given to people with type AB blood.
It is important to note that blood type is not the only factor that needs to be considered when giving a blood transfusion. The blood type of the donor must also be compatible with the blood type of the recipient’s Rh factor.