Answer:
Antibody B
Step-by-step explanation:
According to the ABO antibody grouping, there are two types of antibodies (antibody-A and antibody-B) in the plasma as well as two antigens (antigen A and antigen B) in the red blood cells.
When an individual has a blood group A, he/she has Antigen A in the red blood cell and antibody B in the plasma.
When it is blood group B, the individual has antigen B and antibody A.
When the blood group is O, the individual has no antigens but have antibody A and antibody B.
When the blood group is AB, the individual has no antibodies but have Antigen A and antigen B
Therefore, Tom has antibody B in his blood because he is A+