The correct options are
B Donor - O, recipient AB
C Donor - AB, recipient AB
D Donor - O, recipient O
A person with AB blood group has A and B antigens and no antibody. A person with O blood group has none of these antigens and produces both types of antibodies. The same type of blood group can always be donated. O can be donated to an AB person as the latter will not produce any antibody. A person with O group, however, cannot accept AB blood, as O blood would produce both anti-A and anti-B antibodies.