Which of the following statements is true about blood groupings?

The statement that is true about blood groupings is that Group O has no antigen. Antigens are proteins that are found on the surface of red blood cells, and they are what determine a person's blood type. Blood types are classified into different groups, including A, B, AB, and O, based on the presence or absence of certain antigens. In Group A, the A antigen is present on the surface of red blood cells, and in Group B, the B antigen is present. In Group AB, both A and B antigens are present, while in Group O, neither A nor B antigens are present. Because Group O does not have any antigens on the surface of its red blood cells, it is considered a universal donor, not a universal recipient as stated in one of the options. Group AB, on the other hand, can receive blood from any group because it has both A and B antigens on its red blood cells. Therefore, the correct statement is that Group O has no antigen.