Answer :
answer is C. cause he is homogenous you cant get o and they are passing a and b so it will be answer C. blood type ab
The correct answer is option b. Blood type B
In the question, it is given that Mary has type A blood and her son has AB blood type. In case, the progeny is type AB and the mother is type A then the father must have a blood type B. For the inheritance of AB blood group, the progeny must inherit a dominant allele coding for blood type A and a dominant allele for the blood type B. If the mother is type A, then the child must have inherited the A allele from mother, and the B allele from father. So, blood type B would be father's blood type.