Question

what is the blood group of a person that has neither antigen a nor b, and is positive for antigen d?
a) o negative
b) ab negative
c) o positive
d) ab positive

Explanation:

Blood groups are defined by antigens on red blood cells: type O has no A or B antigens. The Rh factor (antigen D) determines positive/negative status; presence of D means positive. Combining these, no A/B antigens + D antigen gives O positive.

Answer:

c) O positive