The genotype of blood group 'A' can be:

Explanation

Option B is correct. The genotype of blood group 'A' can be AA or AO. This is because the ABO blood group system is determined by the presence of three different alleles of the ABO gene: A, B, and O. The A allele is responsible for the production of the A antigen, the B allele is responsible for the production of the B antigen, and the O allele is responsible for the production of neither antigen.If an individual inherits two A alleles, they will have type A blood. This is because the A allele is dominant over the O allele. In other words, the presence of even one A allele is sufficient to produce the A antigen and type A blood. If an individual inherits one A allele and one O allele, they will also have type A blood. This is because the A allele is dominant over the O allele. In other words, the A allele will mask the presence of the O allele, and the individual will still produce the A antigen and have type A blood. Therefore, the genotype of blood group 'A' can be AA or AO.