9. (2 pts) Blood serum (the antibody containing fraction of blood) is taken fram easc students in a genetics laboratory. Each sample is then tested with red thood cells olstalned from each of the other four students. Agglutination of red blood cells occors is some sers (desighned by a +) but not in others (designated by-). The following table gives the resits observed: Red blood cells from stodent Blood serum from student 4 If the blood type of student I is known to be type A, what are the blood types of the semainitng four students? Explain your conclusions.