Question

a person with blood type b can donate blood to type(s)
__________.
a o only
b b and o
c b only
d b and ab

Explanation:

Blood donation compatibility is based on the presence of antigens. A person with blood type B has B antigens. Type B can donate to those who do not have antibodies against B antigens. Type B has no A antibodies (so can donate to AB which has A and B antigens) and type B can donate to itself (as same antigen). Type O has anti - A and anti - B antibodies, so B blood cannot be donated to O.

Answer:

d. B and AB