D because the others harm the bird instead of helping
Answer:
BbxBb.
Explanation:
If Bb gene is crossed with Bb, the offspring is produced with normal hearing because both the genes are recessive in which the deafness gene hide and the hearing gene is dominant so the offspring can hear sounds clearly. The dominant A gene is responsible for deafness and we can see the offspring BbxBb in which no dominant gene is present. The other three offspring are deaf because of the presence of dominant A gene in their genetic makeup.
