Which pair of parents could have a child with blood group O?
- Aheterozygous father with blood group A and heterozygous mother with blood group B
- Bheterozygous father with blood group A and homozygous mother with blood group B
- Chomozygous father with blood group A and heterozygous mother with blood group B
- Dhomozygous father with blood group A and homozygous mother with blood group O