What is the recommended Rh- genotype for someone who is Rh positive?

The Rh factor is an important aspect of blood typing, determined by the presence or absence of the D antigen on the surface of red blood cells. Individuals who have the D antigen are classified as Rh-positive, while those who do not are Rh-negative.

In this question, the focus is on identifying the recommended Rh genotype for someone who is Rh-positive. The Rh-positive genotype can be represented as either homozygous (DD) or heterozygous (Dd).

The choice indicating DD or Dd accurately reflects these possibilities. A person with either of these genotypes will produce the D antigen, leading to their classification as Rh-positive. Therefore, the correct option reflects the genetic combinations that allow for the presence of this vital antigen.

In contrast, Rh-negative individuals have the genotype dd, which lacks the D antigen. Therefore, this genotype would not apply to an Rh-positive person, confirming that the selection of DD or Dd is the appropriate representation of Rh-positive genotypes.